canada does the same.
if you get pegged a terrorist we want you here. we keep you here. we prevent you from going, you can beg all you want, your not going, you must stay close and cuddle... if you tell the gov you want to leave and go kill people that way they believe its better for you to stay and kill people this way..
and such it happened to us too..by someone who wanted to leave begged even and was told do it here...and so he did.
we just got lucky ours was an amature..and killed a solder and shot up parliement...