[The why is important, but more important is that they did it at all.][link] I’m certain that Facebook, MySpace, etc, got similar requests and complied with them without even thinking.
[link]: http://www.fastcompany.com/1716100/why-twitter-was-the-only-company-to-challenge-the-secret-wikileaks-subpoena “Why Twitter Was the Only Company to Challenge the Secret WikiLeaks Subpoena | Fast Company”