London, UK - Usman Ali has grown used to the routine whenever he passes through an airport on his way in or out of the UK.

As he walks to catch a flight, or shortly after touching down, he says he will be stopped by police and questioned without access to a lawyer and without the right to silence.

His laptop and mobile phone are examined and their data copied. He has also been searched, fingerprinted, obliged to give a DNA sample and photographed repeatedly.

Ali, a London-based Muslim cleric who travels frequently as part of his work for a charity delivering aid to Syrian refugees, says he has been stopped six times this year alone, and many times prior to that, often for several hours.

Police and other border officials are able to do this using Schedule 7 of the Terrorism Act, a controversial piece of legislation that allows them to detain anybody even without reasonable cause for suspicion.

"It's usually SO15 [the Metropolitan Police's specialist counter-terrorism branch] that stops me," Ali told Al Jazeera of a recent encounter at Luton Airport.

"As soon as I sat down, I said, 'Here's my phone, here's my laptop, I don't need anybody informed, I don't need a solicitor, I don't need a glass of water. Just get on with the questioning.'"

Refusal to work as an informant

In terms of the way that MI5 try to recruit individuals, they say things like, 'We know you are one of the worst extremists in the UK but there is a way out of this for you. Come and work for us.' Or they will say things like, 'You weren't allowed into America. We can make that go away for you if you help us.' Asim Qureshi, CagePrisoners' research director

Ali believes he is being targeted by the security services because he once refused to work as an informer for MI5, the UK's internal security agency. On two occasions at different airports in recent weeks he says he was passed on to the same MI5 officer after initial police questioning.

"He said he was informed that I was coming back and that's why he had come down to see me. So I'm obviously on their radar. Their main issues are my views about jihad and do we give money to the rebels [in Syria]."

The legitimacy of Schedule 7 finds itself under fresh scrutiny following the publication of a government report on the issue and concerns raised by David Anderson, the UK's independent reviewer on terrorism legislation, about the copying and retention of electronic data during Schedule 7 stops.

As a consequence of a public consultation, the government announced several proposed changes to Schedule 7 legislation that it says will address some of the main complaints, such as the reduction of the maximum period of examination from nine hours to six hours and giving detainees the same right to legal advice as those held in police stations.

Other contentious issues, such as the lack of need for reasonable suspicion, are currently the subject of legal challenges in UK courts and at the European Court of Human Rights.

Despite his concerns about electronic data, Anderson last week broadly welcomed the government's proposals, noting in his annual report that the number of people examined had fallen by 12 percent to 61,145 in 2012/13.

He said Schedule 7 remained of "unquestioned utility" in combating terrorism, even though nearly 70,000 stops in 2011/12 resulted in just 24 terrorism-related arrests. But he acknowledged: "Undeniably its exercise has given rise to resentment, particularly among Muslims who feel themselves singled out for attention".

CagePrisoners, a campaign group working with communities and individuals affected by counter-terrorism policies, said the proposed reforms to Schedule 7 amounted to "cosmetic changes" and failed to address underlying concerns regarding perceived religious and racial profiling.

"For many Muslims it's not so much that they have been stopped but the type of questioning that accompanies that," Asim Qureshi, CagePrisoners' research director, told Al Jazeera. "For example, they get asked, 'What type of Muslim are you? What are your foreign policy opinions? What are your views on Palestine?'”

"None of those questions pertain to whether that person poses a credible risk to UK security. It's a fishing exercise that's not got anything to do with any immediate security concerns. Of course this creates resentment."

No clear rules governing border stops

Mike Rispoli of the privacy campaign group Privacy International said there were no clear rules governing border stops, especially regarding access to electronic data.

"The fact is that when the Terrorism Act was passed [in 2000] phones were very different to what they are now," he told Al Jazeera. "Now our phones carry so much information. They have pictures, they have browsing history and location information, along with text messages and phone numbers. We are operating in a legal framework that is woefully outdated."

Ali is a controversial and, in some eyes, extremist figure who holds views with which many people in the UK, both Muslim or non-Muslim, would strongly disagree.

He is a former member of al-Muhjaroun, a now banned British-based Islamist group, but says he split with the group over tactics in 2003.

He advocates jihad as a "God-given right" in countries he considers to be Muslim lands and believes that political and legal systems in Islamic countries should be based on Sharia law.

And he acknowledges that his work in Syria, which he says is humanitarian, attracts attention at a time when Anderson's report says the country has become "a highly attractive destination for UK extremists wishing to engage in jihad".

In 2006 Ali was arrested and held for nine days as part of an investigation into a plot to blow up the Canadian parliament, but was released without charge. He says one of those involved had his phone number in his mobile after meeting him at a conference.

Regular stops and harassment

He said MI5 officers subsequently approached him on two occasions, the second when he went to a police car pound where his car had been held after his arrest.

"They said, 'Look, we know you're broke. We can help you'," he recalled. "And then they opened a briefcase. I swear to God, I have never seen so many bundles of banknotes. And they quite literally put it in my hand and said, 'Take it, it's all yours. We'll talk about it later.'”

"I said, 'There is nothing I can do for you I am not going to act as an informant for you. I am not going to live on your payroll for the rest of my life. Just leave me alone.' I stormed out, grabbed my car and got out of there."

Ali believes his regular encounters with security service agents at airports since then amount to harassment, and says he has been deliberately made to miss flights by Schedule 7 procedures.

"I think that partly it is because of my refusal to work with MI5. I think it has now come to a point where they are trying to put me under pressure," he said.

"One time I was stopped, I said, 'Look be honest, why have you stopped me?' And the guy said, 'It's got nothing to do with us. We get told from higher up and we are just doing our job.'"

A spokesperson for the Home Office, which handles media inquiries regarding MI5, told Al Jazeera it did not routinely comment on individual cases.

But, in a statement, it said: "The government takes all necessary steps to protect the public from individuals who pose a threat to national security.”

"Schedule 7 forms an essential part of the UK's border security arrangements, helping to protect the public from those travelling across borders to plan, finance, train for and commit terrorism. We want to ensure these powers are used proportionately, and are both necessary and effective."

Qureshi said Ali's account rang true in terms of experiences reported by others approached by the security services.

"In terms of the way that MI5 try to recruit individuals, they say things like, 'We know you are one of the worst extremists in the UK but there is a way out of this for you. Come and work for us.' Or they will say things like, 'You weren't allowed into America. We can make that go away for you if you help us.'"

While Anderson has urged those stopped under Schedule 7 to raise their concerns with the Independent Police Complaints Commission, Qureshi said that failed to recognise the "climate of fear and acceptance" that existed in the Muslim community.

CagePrisoners has set up a website called Schedule 7 Stories, where it encourages those stopped to report their own experiences as well as offering advice on how to handle border interrogations.

"The fact of the matter is that all of us have lost hope in the system. Now we just go and get on with it," said Ali.

"I keep on saying to them, 'What is the point? I think you know by now that I don't have any terrorist numbers or terrorist materials or terrorist connections. You've detained me so many times and you haven't found anything.'”

"'I'm not talking about everybody else, I'm talking about me. Why do you keep holding me under the Terrorism Act but you say that you don't deem me to be a terrorist?' It's a contradiction."