Additionally, it is worth noting that the weakest target is very often the human element. Although this was noted by Mitnick in his "hacking" (which generally was just clever social engineering), it is equally true when governments are targeting you. The stasi (or other pernicious organizations organized to carry out state censorship) could easily have someone smeared in the press, dismissed from their job, or many other means short of official imprisonment.

To the point of encryption, as noted by the NSA (inclusive of present revelations), it actually makes you a target for state surveillance. This is a bizarre catch 22. If you are using facebook and "rah rah-ing" about Obama or the latest political fever you probably are at very little current risk of long term data retention. The government doesn't care about you. If you slip into politically suspect views and/or start encrypting your messages simply because you don't want the government to read them, you attract government attention, including the likely possibility that your communications will be retained.

Moreover (and this is where it gets scary, even if it wasn't already), the likelihood is that the many people that are part of your social graph (even if you aren't involved in social networks, some friends likely are and have probably shared their email contacts at the very least), governments can very easily figure out your social circles, and how suspect they may be from any standpoint that the government cares about.

Today this may be "terrorism" (itself a vague term, but one that at least nominally includes the threat of violent acts), tomorrow it may simply be having politically incorrect opinions of some variety. As noted by many, even the nominal but legally actionable protections for American citizens have been eroded to the point that the executive branch can hold anyone in infinite detention without trial. A world without borders has become the panopticon, a jail where we are bound by ever-peering eyes of our peers.

"What you say, can and will be used against you in a court of law" -- even if you said it 10 years ago when you were drunk in a private message on Facebook.

Welcome to the Brave New World.