Governments, Led by U.S., Seek More Data About Twitter Users
bits.blogs.nytimes.com
bits.blogs.nytimes.com
Thus far, only established, large corporations seem to have been targeted by the NSA, with a few exceptions. Twitter in particular has apparently been quite resistant, but I think compliance becomes inevitable. Supposedly Qwest's CEO was jailed for refusing call detail records, for instance: http://www.businessinsider.com/the-story-of-joseph-nacchio-a...
I realize this wouldn't protect from individual attention.