That's part of the idea of proportionality in human rights law, which says that certain civil rights can be suspended in times of emergency—for example, if we were at war, with tanks rolling in the streets. You see that happening and it's not necessarily illegitimate, but when you suspend something like that for something like the threat of terrorism, which is an indefinite threat that we're going to be facing, then there are real challenges. These suspensions and exceptional circumstances need to be taken in a time-tested manner.
On October 21st, 2016. See this statement in context.