How many terrorist attacks would there be if no one was trying to stop them?
BTW, NSA never prevented any terrorist attack: https://en.wikipedia.org/wiki/Global_surveillance#Purposes
Upd: Also, if the risk is already small, why we need even more privacy invasions?
> NSA never prevented any terrorist attack:
> The director of the National Security Administration today told Congress that more than 50 potential terrorist attacks have been thwarted by two controversial programs tracking more than a billion phone calls and vast swaths of Internet data each day.
http://abcnews.go.com/Politics/nsa-director-50-potential-ter...
https://www.theguardian.com/commentisfree/2013/sep/25/nsa-re...
> Unfortunately the tools available to terrorists continue to change and so must the measures used to fight them.
From what I know, the current problem is not the lack of information, but how well it is targeted. For example, we knew about the terrorists in France in 2016: https://en.wikipedia.org/wiki/March_2017_%C3%8Ele-de-France_...
Also, many think that the war on terror made more harm to the humanity then what we would have otherwise. At least such invasive war.
https://en.wikipedia.org/wiki/Criticism_of_the_War_on_Terror
No one. But some claim that the current risk must decrease, while it is much smaller than almost everything else.