In general, no. When you start assuming everyone is a bad guy you end up with everyone from journalists to drug dealers to captains of industry trying to make sure their own secrets are safe from the surveillance machine.

The surveillance people have a saying. To find a needle in a haystack first you need a haystack. But you don't want a bleeding haystack, you just want the needle -- and now you've put a haystack on top of it. Now all the good guys are developing and using anti-surveillance methods.

The bad guys were already assuming they were under surveillance. They aren't being deterred by surveillance of everybody else, they're just getting access to new tools developed by the good guys, and are aided by the fact that anti-surveillance methods are no longer suspicious.