We have always had the occasional psychopath next door. Moreover, communication has always been a double-edged sword, available to criminals and law enforcement alike. The problem is that regulation has not kept up with technology. For years we have had strict laws about phone wiretapping and opening mail, to protect ordinary people from the abuse of law enforcement authority. When criminals still relied on these methods to communicate, police were still able to track and prosecute them despite the restrictions. Now we have email, social media, and cellphones. Average folks need to be able to rely on comparable protections, and law enforcement authorities need to learn to work within them.
That being said, people make much more public now than they used to. Posting your life story, or even the account of your day, on Facebook is the equivalent of putting that letter to your sister on the bulletin board at the local diner, or worse. If you wouldn't have done that, then get off Facebook. Everyone who complains about government (or corporate) snooping and data collection should look first at what they themselves willingly give out. If you mimize exposure, however, just providing contact and payment info when shopping online, communicating with friends via individual emails, etc. you should not have to worry that these interactions are subject to tracking and eavesdropping unless you become a legitimate target of investigation, just like in the old days.