Yeah, that’s the problem. Terrorism laws were a kneejerk reaction to 9/11 and 7/7 that handed sweeping undemocratic powers to ministers without adequate checks that liberal-minded people have consistently been saying would lead to exactly this kind of obvious abuse. The courts have little choice but to accept it - the time to stop it was when the law was passed, but no party (except maybe the Lib Dems) would overturn it because liberalism is dead and not a vote winner.