Traffic to Wikipedia terrorism entries plunged after Snowden revelations
Of course mass surveillance leads to a chilling effect. Personally, I'm now concerned about what I say in email, in text messages, in discussion forums, and in telephone calls. I fear that if I use the wrong words or visit the wrong websites, I'll trigger some automated system and will be put on some kind of watch list that will change my life. This is a very scary state of affairs. And unfortunately I don't see a near-term solution. The interests of government and corporations are aligned (reducing pressure to enact any serious privacy regulation). They're both looking to vacuum up as much personal data as possible for national security on the one hand and to develop new and improved revenue/business models on the other.