Already, governments from Canberra to Brussels to Washington have made moves to expand surveillance powers or enact new limitations on speech in the wake of this tragedy.

But more surveillance is not necessarily better surveillance, and increasing the scope and scale of government spying or interfering with freedom of expression is not the answer to all our security or societal problems. French officials have admitted they had prior intelligence, which suggests that neither did inadequate surveillance contribute to these horrific attacks, nor would heightened surveillance have prevented them.