On a sunny Friday in the last week of March, a group of protesters gathered outside London's Metropolitan University. Noticeably older than the students who filtered in and out of the building's glass doors, the motley crew of assembled activists shouted slogans confidently and waved placards energetically. They had clearly done this before.

The 15-or-so men and women were calling for the resignation of Bob Lambert — a former undercover policeman and current university lecturer whose double life was discovered relatively recently. In October last year, the mother of the child he fathered while undercover was awarded 425,000 pounds ($663,000) by the London Metropolitan Police.

"Are you the pervert?" one of the protesters asked an amused policemen that stood nearby. "No, he's not," another replied.

We were standing on Holloway Road, north London. The demonstrators weren't allowed inside, so instead they handed out fliers and attempted to get passing students interested in the fact that one of their lecturers was once a police spy who used relationships to get close to targets, before abandoning his child to return to his other family.

The activists haven't managed to find out much about Lambert's activities within the university, though they did manage to get hold of his telephone number. "We don't even know if he lectures today," one noted dolefully.

* * *

The scale of the operations carried out by undercover police on protest groups in the UK over the past half century is slowly coming to light, and many of the disclosures have been shocking to the extent that they seem implausible.

Undercover police officers who infiltrated animal rights, anti-fascist, anti-racist, and environmental groups have lived for years as activists, had long-term sexual relationships to provide cover, and adopted the identities of dead babies. Those believed to have been spied on include the parents of murdered black teenager Stephen Lawrence and the family of Asian student Ricky Reel, who went missing 18 years ago.

The most notorious undercover unit was the now inoperative Special Demonstration Squad (SDS), founded in 1968 and active for 40 years. The unit's members adopted more than 100 different identities. Its recently leaked tradecraft manual recommended that employees get tips on acquiring dead people's documents from Frederick Forsyth novel The Day of the Jackal and included suggestions on how to gain adequate cover: "If you have no other option… you should try to have fleeting, disastrous relationships with individuals who are not important to your sources of information."

Lambert, who went by the name Bob Robinson, was just one of an unknown number "deep swimmers" — as they called themselves. During his time undercover between 1984 and 1988, Lambert was arrested numerous times, co-authored the McLibel leaflet, had relationships with four women, and fathered a child that he left soon afterwards.

Protest groups targeted by undercover police claim the infiltrators would often act as agent provocateurs, encouraging illegal acts among peaceful protesters, and say that some participated in illegal actions themselves. As the details of the web of surveillance are revealed, at least 57 protesters have now had prison sentences quashed or prosecutions dropped as a result of evidence given by undercover police officers being inadmissible.

The activists have led the efforts to track down and expose the undercovers — both from the SDS and from subsequent units — but it's taken a toll. Many told VICE News that they still find it difficult to trust people, now aware that any seeming paranoia could never balance the lengths that the state has proven it was willing to go to find out information about them and their often quite humdrum activities.

Following regular calls for a thorough inquiry into how systematic and organized this behavior was, British Home Secretary Theresa May finally announced the terms of reference for the latest investigation on Thursday. Originally promised in March, the inquiry will be led by Lord Pitchford, is expected to be completed within three years, and has given activists — both operative and retired — some hope that they'll finally get the truth about the extent to which their lives were trespassed on.

* * *

The first time we spoke, veteran activist Alex Hodson warned me about how wary he and his colleagues are. When we finally met he seemed cautious and was wearing sunglasses, but spoke with animation.

"I worked quite closely in the past with people who later turned out to be police spies — undercover policemen — and I've had close friends who have had relationships with some of these people," he said. "I've seen some of the damage it was doing to people in those campaigns when they were finding out that some people were undercover. And so I've kind of been involved for several years trying to uncover people and just trying to publicize the careers of some of those people."

Hodson was involved in a wide selection of protest groups. One of his friends who later turned out to be a policeman was Jim Boyling, whom Hodson met at a Reclaim the Streets event. Boyling was undercover between 1995 and 2000.

Hodson said that female friends of his had relationships with activists who turned out to be undercover police officers, believing they had met someone who thought similarly to them. "For those women… the lasting trauma is very evident," he said.

"A very close friend of mine finds it very difficult to trust people. She went through periods not knowing if anyone she knew was a genuine person. Finding out that her ex-boyfriend was an undercover policeman threw her whole world into doubt. Someone she thought was her soulmate. And other women I know, it's completely thrown their lives upside-down. People are in therapy. Some people have resolved never to have fun relationships with people who they haven't known since they were very young, haven't known for like 10, 20 years. Because they just don't know who they can trust anymore. It does totally undermine the sense of who you are."

A common tactic among the policemen was to begin to display the signs of a breakdown before leaving their position, Hodson said. Then they would completely vanish — often saying they were moving abroad.

"Unless people are careless or you get a tipoff or you really, really are very suspicious of somebody, you don't really know," Hodson said. "For quite a lot of these people there were suspicions, but no one could really pin it down to truth for a long time."

Can someone really just disappear? "People do do that," Hodson observed. "It's kind of a youth thing for many people. So people do go into it when they're young and as people grow up they do kind of change their ideas. They start doing other things. It's something they're growing out of."

Years, later, when the activists became more questioning and began a long struggle to piece together everything that happened, some discoveries came completely down to luck.

Undercover policeman John Dines, who served from 1987 to 1991, was outed after his ex-girlfriend Helen Steel tracked down his real name and located his marriage certificate, which listed his occupation as a police officer. Mark Kennedy — undercover between 2003 and 2010 — was detected because he accidentally left a passport with his real name on it lying around his house.

Hodson was one of those involved in locating Lambert — who has reinvented himself as an expert on Islamophobia. Together with a friend, Hodson attended a conference Lambert was speaking at. "We actually filmed him speaking and showed it to one of the people who went to prison as a result of [Lambert's surveillance] and they said yes, that's him."

Lambert was clearly exploitative, Hodson said. As to how systematic his behavior was and how aware the Metropolitan Police were of it, Hodson said: "These people are very highly trained at getting close to people, very highly trained at telling them what they wanted to hear, making them feel like this was a soulmate… And they deliberately got close to people, moved in with people they were having relationships with, formed sexual relationships which they walked out of… They were trained to do that by the police. It was a tactic."

Scotland Yard has denied that they ever had a policy that officers could use sexual relations for the purposes of policing.

Hodson continued: "Whatever the Metropolitan Police say now they were aware of that and they've had that information… The point is that this was a pattern; this was a way of getting close to people, a way of both finding out about those people but also bolstering their own cover and making themselves more believable."

* * *

The protesters who gathered outside the Metropolitan University in March were a varied bunch. One elderly man was convinced to join them after walking by and being drawn in by the group's stories. Another woman at the demonstration, who gave her name as Toby, said that she became aware of the issues around undercover policing through her work in local community groups. "One of the women [who attended] was directly involved with the police spies and it's really horrible for her. Still is, it's been damaging and the whole thing is nasty."

Toby — from North London — told VICE News she felt compelled to demonstrate to try and make people aware of what has been going on, and that she thinks spying by the police is "anti-democratic."

"I think to be realistic you've got to assume that at any meeting or gathering you're at that there will be at least one spy there, but that mustn't stop you taking action and having meetings, networking and all the rest of it. Because if you start to get paranoid and pretend that you can filter out people then they've won."

Lindsay Hunt, 37, who wore glasses and his red hair long, held a sign that read: "Sack Bob Lambert: London Metropolitan lecturer, police spy, agent provocateur, abuser of women."

Emphatic about the damage inflicted by the undercovers, Hunt said that the actions done by the SDS represented "one of the most corrupt and dark corners of Metropolitan police history."

Hunt said he wanted a proper public inquiry and testimony under oath, though he didn't expect the full truth to emerge. He pointed to other investigations, such as the Leveson and Hillsborough inquiries, saying fact-finding had to be regarded as a lengthy process. "It's a long-term injustice done to you, and then there's the cover-ups that follow and you try and prise it apart," he said. "You get something out of each of these, and if you collect all the nuggets then you start to make a sort of pile."

Hunt was friends with Mark Kennedy, another former policeman. During his time undercover — 2003 to 2010 — Kennedy had relationships with at least three women and is believed to have used his fake passport to travel to more than 40 foreign countries.

"I knew Mark Kennedy for the full seven years," Hunt recalled. "We were close and I was one of the people who investigated him."

Hunt said that Kennedy, "like most of the rest of the undercover cops we exposed, was a massive drinker. And when he's blind drunk nothing slips. You or I, you'd start to have some crisis of conscience or feel a bit… Nothing, never. Probably he'd fool everyone you'd ever met."

On how a human could be so duplicitous, Hunt said you had to try and conceptualize the feeling of control that might accompany it. "You felt like God, because you were the only person who knew both sides," he speculated. "You can choose what to tell and you've got the most power in the room."

Hunt pointed out that Kennedy hired infamous publicist Max Clifford to advise him after he was outed. In an interview with the Mail on Sunday, Kennedy stated: "People like to think of things in terms of black and white. But the world of undercover policing is grey and murky. There is some bad stuff going on. Really bad stuff."

Like all the other activists VICE News spoke to, Hunt believes that inconceivable levels of surveillance by the government are ongoing. "If you speak out against the government you are a target, or if you know someone who speaks out against the government you are a target," he claimed. "Files will be kept so that you don't do that and they conflate any threats to the established political order are the same as threats with guns and bombs. It's still all going on."

Hunt still displays confusion when speaking about how "wildly improbable" it is that the police would put such huge resources into spying on activist groups, "that they would take people and take their lives off them to put them in to spy on climate campaigners and stuff, and especially the relationships." Kennedy was living with his partner at the time he disappeared — they had been together some six years.

"He wasn't even doing that much activism at the end," Hunt said. "Almost all of it wasn't politics that he was with us. Almost all of it was social time."

Kirk — who asked to be referred to by his first name — said he was also acquainted with Kennedy. "I knew Kennedy as well, he's very convincing. When I found out I was completely gobsmacked. The guy is covered from head-to-toe in tattoos, he's got long, lank hair, loads of piercings, huge piercings in his ears, he DJs bass at the local anarchist social club, he raves with the rest of us."

Plus, Kirk recalled, Kennedy had "the most money in the room as well. He had so much money."

* * *

"The more open and the more aware we are the more we can actually deal with it," Peter Salmon told VICE News, adding that the public needs to be notified of the extent to which the state is willing to intrude on their lives and the lack of accountability that there can be around surveillance.

Salmon, 41, was mainly active in animal rights and environmental movements, and Kennedy was the DJ at his wedding. Now Salmon operates under an alias and runs the Undercover Research Group — a project that sees him in daily contact with five others, all attempting to track down the rest of the policemen who spied on them. The group publishes their findings online and has been working together for about two years.

"I've been an activist for two decades now and so we've been aware for a long time that there have been undercovers, so it's been something that has bubbled away behind the scenes," he told VICE News by phone. "But the scale of the police informing, because of its nature, because its much more tightly controlled by the police, that wasn't understood until essentially the Kennedy story broke."

The Dublin-born man, who grew up in Northern Ireland and has lived the last 20 years in London, said that he feels it's necessary to properly detail and document what went on "so that people can learn, knowing what happened in the past we can learn how to protect for the future."

His group gets approached by activists who have suspicions about an individual. "There are ways and means for actually looking at somebody and saying there's a genuine suspicion here, we need to take this forward," Salmon said. "So it's slowly working with groups to try and pin them down."

On the upcoming inquiry, Salmon said that while he's usually skeptical of inquiries, he expects this one to "open a can of worms."

"Stuff is already starting to come out into the public so it will be a lot harder for the police to try and pretend that it's just one or two officers," he said. "When the Kennedy stuff originally broke they said he's just a bad apple, but now it's just pretty much every undercover we've encountered has had sexual relationships and quite a few have committed illegal activities."

The span of the inquiry will also be huge, Salmon observed. "It's 40 years of just the SDS alone before we even get on to the more modern units."

Salmon told VICE News that he was unwilling to be identified by his real name because he's concerned about retaliation. "We're going up against the state here," he said. "I've encountered the state for many years; I've had undercovers close to me so I'd rather protect my privacy."

* * *

In their seminal book _Undercover: The True Story of Britain's Secret Police, _Rob Evans and Paul Lewis kickstarted the process of properly documenting the actions and abuses carried out by undercover police officers in their quest for knowledge about protest groups.

In the first chapter, the authors call the phenomenon of an inquiry a "potent weapon" often used by authorities to quell dissent. They write: "Inquiries are strange phenomena. They lend the appearance of probity, but rarely achieve much, except the avoidance of awkward questions… The more a controversy persists, the greater the number of inquiries that are launched. It is a game that can last for years."

The first inquiry into undercover policing of protest groups was launched in January 2011, right after Kennedy's role was publicized. By 2013, 14 more had been announced.

"I'm just hoping that we'll get a wider exposure of what's gone on and this isn't just a whitewash operation," Labour Party MP John McDonnell told VICE News. "I think there's a real anxiety that there could be a situation where there could be coverups, delays in providing of information, inaccurate information being provided, and we could be going around the same circle again as we have done with previous inquiries."

He continued: "It's all about accountability and the rule of law and at the moment it's quite clear from what we know so far and the limited information that we've got so far that the rule of law became almost irrelevant, there are some of these agencies that were undertaking surveillance and that there's been no accountability to any democratic bodies in terms of what's gone on."

On whether these tactics are still being used, McDonnell said that he is convinced they are. "Absolutely convinced and until we have full exposure at the inquiry I don't think there's any confidence… in the police or security services."

However shocking a discovery might be, McDonnell noted, "the water soon closes over those revelations and the state just moves on as though nothing has happened. Now, what I'm concerned about is that the Pitchford inquiry could be just another cleaning up exercise by the state without any real objectives achieved, and what I want is full exposure but also some proposals for legislative reform so that we can get full accountability and some form of openness and transparency."

After hearing the new terms of reference for the upcoming inquiry, Jacqui — the mother of Lambert's child, a boy now in his 20s — told VICE News: "In general I'm happy with the brief terms of reference for the undercover inquiry which have been published today. I think that Lord Justice Pitchford, the inquiry's chair, now has a real opportunity to carry out a robust investigation into how undercover policing went so badly wrong and wrecked so many people's lives.

The animal rights activist, now a law lecturer, said: "It's too early to judge if this inquiry will help restore public faith in undercover policing. I will wait to hear further from the chair on who the inquiry's core participants are, and whether the police will be allowed to hide behind an anonymity provision before I fully get behind this inquiry."

In the meantime, many more court cases against the Metropolitan Police are pending. Police Spies Out Of Lives, a support group for eight more women who had relationships with undercover police officers, also released a statement in response to the inquiry. "Our attempts to uncover the truth through the courts have been met with determined and at times extremely offensive attempts by the police to avoid any disclosure on these issues," it read.

"Now is the time for full and frank disclosure for all victims of undercover policing and public scrutiny of the abuses committed by these units. We sincerely hope that the inquiry will prove to have the power and the political will to overcome the obstacles it is likely to face."