Behold a new legal threshold: let's call it the 007 standard. Apparently the law now allows secret agents to get up to all manner of mayhem, just so long as it's something James Bond might have done. Threatening to strangle a woman with her own bikini top? Powering a speedboat, both on and besides the Thames, destroying everything in your wake? Forcing a shark-gun pellet into a man's mouth, so he blows up like a balloon. All fully lawful, m'lud: can I refer the court to Diamonds Are Forever, The World Is Not Enough and Live and Let Die?

This new principle of jurisprudence was unveiled at the high court this week by Mr Justice Tugendhat, as he ruled on whether a case brought by 10 women and one man duped into fraudulent relationships by undercover police officers should be heard in open court or in a secret tribunal.

The decision hinged on whether the law governing agents of the state allows them to form sexual relationships with those they spy upon. The good judge believes that when MPs wrote the Regulation of Investigatory Powers Act (Ripa) in 2000, permitting undercover police to form "personal or other" relationships, they must have meant it to include sexual relationships. After all, the legislators were bound to have had one particular secret agent in mind. "James Bond is the most famous fictional example of a member of the intelligence services who used relationships with women," Tugendhat declared, lending "credence to the view that the intelligence and police services have for many years deployed both men and women officers to form personal relationships of an intimate sexual nature".

That came as a shock to the women involved in the case, and not only them. The former director of public prosecutions, Ken, now Lord, Macdonald, thought the judge's mention of 007 "ludicrous". Ripa, he told me, is an extremely serious piece of legislation, "one that determines the extent to which our private lives can be intruded upon by the state. It's undermining of parliament's reputation as a serious body to suggest it took into account the mad escapades of a fictional spy".

Talk of Bond only highlights one of the absurdities at the heart of this sad, strange saga that first came to light two years ago, when the Guardian revealed how a police officer named Mark Kennedy had infiltrated the environmental protest movement and become intimate with the activists he was monitoring. The absurdity in question is that of proportionality. At least Bond was confronting mighty adversaries with demonic ambitions to destroy the world: no wonder he had to cut the odd ethical corner. But Kennedy and the other cops were, mostly, targeting domestic groups that posed no such threat. It's true that one undercover policeman caught the Animal Liberation Front activists who had planted incendiary devices in fur-selling department stores (at night, with no one around) – a policeman who has himself been accused in parliament of detonating one of the devices – but the target was usually more Citizen Smith than Dr No. In one case, the police infiltrated an anti-war group called the Clown Army whose existential threat to national security consisted of running around Leeds city centre brandishing feather dusters. Blofeld, it wasn't.

But that the judge thought to mention Bond is perhaps revealing. For even those who would defend Ian Fleming's character from charges of misogyny would concede that he often regards women as disposable. And that is the crux of this case, brought by a group of women who believe their innermost lives were regarded as so valueless they could be used by covert police as mere props, devices to shore up agents' cover stories and prove they were good-faith activists rather than frauds.

Some may question how much the women involved really suffered: they were with a man long ago who was not what he claimed to be – OK, not nice, but move on. Such an attitude was hinted at in the remarks by a male activist who slept with an undercover policewoman in a tent at a "climate camp" and who told the Guardian he did not want to sue the police because the one-night stand was "nothing meaningful".

But for the others these were not one-night stands, they were relationships of long standing – six years in one case, five in another – that were enormously meaningful. Those involved tell of deep and genuine attachments, the men integrated into their lives as partners, living together, travelling together, attending family gatherings, sitting at a parent's bedside, even attending a funeral.

There are at least four children from these relationships, some of whom have only now, decades later, discovered who their father really was – and that they were born of a great act of deception.

The greatest pain seems to have come afterwards. Uncannily, most of the relationships all seem to have ended the same way: a sudden departure, a postcard from abroad, and then silence. Some women spent months or even years trying to work out what had gone wrong, travelling far in search of answers. Others found that their ability to trust had been shattered. If the man they had loved turned out to be an agent of the state, what else should they be suspicious of? Could they trust their colleagues, their friends? And the question that nags above all others: was it all a fake, did he not love me at all? One woman tells friends simply: "Five years of my life was built on a lie."

There was rightly an outcry about the News of the World's hacking of people's voicemail messages. But this was the hacking of people's lives, burrowing into the most intimate spaces of the heart in order to do a job, all authorised by the police. It is state-sanctioned emotional abuse.

The present tense is appropriate because there is no reason to believe this kind of police activity, begun in 1968 when Scotland Yard started to infiltrate groups opposed to the Vietnam war, has stopped. The police have not apologised or vowed to give up the practice. Instead, they simply refuse to confirm or deny that the men involved worked as agents at all. A dozen people are taking legal action in total, but those who have followed the case closest – the Guardian's Paul Lewis and Rob Evans – are convinced there are many more victims, including some who still don't know that a past partner conned them. Almost every undercover cop so far identified found himself a lover in the group under surveillance: it was the norm, a standard part of their tradecraft.

This is a question for the police, whose view of women as so dispensable surely suggests a kind of institutional sexism, but also for the state itself. Either it knew or it didn't know what these men were up to, apparently in the service of the crown: both possibilities are indefensible. There is no licence to kill, and there can be no licence to break human hearts, to inflict lasting psychological trauma. The James Bond stories are thrillers, not an instruction manual for an unaccountable state.

Twitter: @j_freedland