This is the CAGE that defends the rights of terrorists like Jihadi John
Even if he was the late Bearded Wanker Johnny himself, this does not free us from the obligation to apply due process and the list of various rights (which do not exist in Britain anyway[*]) such as presumption of innocence, right not to self incriminate, etc. This is what makes us fundamentally different from Bearded Wanker Johnny and his mates. By the way do not even get me started on his extra-judicial termination without an appropriate death penalty in absentia being served onto him by court.
[*]The only concept of fundamental right in English law comes from the EUHR convention. There is NO other right which is considered fundamental and irrevocable - something which "Parliament is Sovereign and Shall Not Be Bound" has proven by amending the original Bill of Rights of 1689 until there is nothing left of it. Reading it is a very educational experience for anyone claiming that UK has a stable legal system and a rule of law.