A terror suspect today failed in a bid to lift an order which limits his movement and access to mobiles phones - and forces him to wear a monitoring tag.
The suspect - identified only as CD - had asked a High Court judge to relax measures imposed under legislation aimed at combating terrorism.
His lawyers argued that restrictions applied under the 2011 Terrorism Prevention and Investigation Measures Act were not necessary.
And human rights campaigners have criticised such measures as "punishment without trial".
But Mr Justice Ouseley said a "realistic" assessment of evidence showed that restrictions had been effective and were protecting the public from CD's "terrorist-related activities".
He concluded - after carrying out a statutory review of the restrictions at a High Court hearing in London - that the control measures were "justified", "necessary" and "proportionate".
CD - who is in his late 20s and has joint UK-Nigerian nationality - hit the headlines after Home Secretary Theresa May made him the subject of a control order under the 2005 Prevention of Terrorism Act in early 2011.
One requirement of that order - ratified by the High Court in July 2011 - was that CD had to be moved from north London to an address in the Midlands.
But new legislation - which says a "relocation requirement" cannot be imposed - meant that fresh restrictions had to be applied, said Mr Justice Ouseley.
The judge said CD had been returned to London and new restrictions imposed under the 2011 Terrorism Prevention and Investigation Measures Act in December 2011.
New control measures included an overnight curfew, restrictions on travel and limitations on access to mobile phones and computers.
And Mr Justice Ouseley said he had reviewed evidence, read assessments by the security services and concluded that the fresh restrictions were fair.
The judge said he thought restrictions had made CD decide to "keep a low profile".
"The (measures) are having something of their intended effect," said Mr Justice Ouseley.
"If it is possible to say the absence of activity is down to a change in or absence of intent or outlook or ability to engage in terrorist-related activity... it is far more reasonable to consider, as does the Home Secretary, that it is the effectiveness of the (restrictions) which is protecting the public from his terrorist-related activities."
He added: "I accept the security service assessment as to what the risk is if (restrictions) were to be removed."
In July 2011, another High Court judge had come to similar conclusions when reviewing the necessity for a control order imposed under the Prevention of Terrorism Act.
Mr Justice Owen had said he was satisfied that there were reasonable grounds for suspecting that CD was a "leading figure in a network of Islamist extremists based in north London and has been involved in planning an attack or attacks on members of the public".
An MI5 witness had said it was "strongly assessed" that CD had attended a terror training camp on farmland in Great Langdale, Cumbria, in 2004.
And it was suggested that four men who unsuccessfully attempted to cause explosions on the London Underground on July 21 2005 had also been at the camp.
The High Court was told there was evidence that CD underwent further training in Syria for three years and, while there, began planning a terrorist attack against the UK.
On his return to the UK in April 2009, the attack planning continued and he and his associates made several attempts to obtain firearms, the court heard.
Lawyers for CD argued - before Mr Justice Owen and Mr Justice Ouseley - that MI5 reports assessing the danger CD posed were flawed and restrictions were unnecessary.
And human rights campaign group Liberty has criticised control measures imposed under anti-terrorism legislation as "punishment without trial".
A spokeswoman said, following a High Court hearing in July 2011: "If there are such clear allegations that someone has been training for terrorism, attempting to procure arms and meeting with co-conspirators to plan atrocities, he really must be charged and tried."