I am going to make an assumption that any 'terrorist' that plans their next attack through facebook or gmail is more of a threat to killing themselves by a bomb backfiring, than to the public.

Mass surveillance is not the solution.

Also, their claim that 'they operate fully within the law' is just a claim without any public evidence to back it up, if all three of them were subject to a polygraph during this then I might take it a bit more seriously. Otherwise, why should I be inclined to trust the words of a organisation that clearly does not trust me?