A really thought-provoking post by Arvind Narayan on Freedom to Tinker begins:
As a computer scientist who studies Privacy-Enhancing Technologies, I remember my surprise when I first learned that some groups of people view and use them very differently than I’m used to. In computer science, PETs are used for protecting anonymity or confidentiality, often via application of cryptography, and are intended to be bullet-proof against an adversary who is trying to breach privacy.
By contrast, Helen Nissenbaum and others have developed a political and ethical theory of obfuscation, “a strategy for individuals, groups or communities to hide; to protect themselves; to protest or enact civil disobedience, especially in the context of monitoring, aggregated analysis, and profiling..”
What are the implications of using encryption as protest? Arvind writes:
The key difference when encryption is used as protest is that it is a collective and participatory activity, rather than individualistic. Such users hope, in conjunction with other users, to make life a little bit harder for the powers that be and to protest the surveillance regime. Further, they would like to signal to their peers that they are conscientious citizens who will not accept the status quo. 
As a corollary, users will seek the simplest possible tools to achieve the objectives of protest and signalling, even at the expense of security. This is because there aren’t any major personal benefits to encrypting nor any repercussions from the encryption being defeated. It’s a bit like recycling — we’d like to act responsibly, but won’t do it if it’s too hard. Of course, users always favor convenience over security more than developers would like, but this is an extreme version.
Read his whole essay here.