Twitter Banned from White House
readwriteweb.com
readwriteweb.com
Seriously though, do we want our taxpayer-paid public employees wasting as much time at work on Facebook as we do? I doubt it. People forget that the White House is an office too, just like others - just with lots of special properties.
Pretty much all communications coming in and out of the WH have to be monitored and recorded - either at the summary level (sender/recipient/subject/date) or at the full-text level, owing to laws about public access and documentation in the National Archives. Interested parties can FOIA pretty much anything produced by an employee of the government; electronic communications are no exception. So until NARA can created a Twitter/Gmail/Facebook proxy - for which I wouldn't stay up waiting - I suspect they'll just keep blocking them.
"If you require access to this site for business reasons, please fill out this form in triplicate and sign in blood..."
If they don't have a way to keep tabs on any messages that get twittered, sent via facebook or even worse, webmail; then it's far easier to just block it.