Doing consulting in insurance companies, I can tell you Facebook have been banned for a long time, and twitter more recently. As an outside consultant I have gmail, but the employees sometimes don't have it.
I work in a big insurance corp, Facebook not banned there, but twitter and friendfeed were blocked after they appeared on tv or made the news by getting bought for millions. Blocking remains arbitrary and ineffective as about 2/3rds have iphones or similar. RSS remains the way round all the muscle flexing of IT depts, I'm amazed it hasn't been understood mor
I'm guessing the reason RSS isn't cracked down on more is because not enough people are using it. That makes cracking down on it not worth the trouble.
