During a hearing in congress recently two supreme court justices were asked about what role social media does and should play in their lives. Here is what they had to say:
As hilarious as it is to watch old frumpy people bumble their way through talking about social networking I think this actually raises an important question. Should the justices have twitter profiles or facebooks? Both Kennedy and Breyer seem to think they shouldn't. That would be my first inclination too but I'm not so sure.
Certainly it wouldn't be proper for a supreme court justice to create a celebrity fan page for themselves to invite personality worship. It would also be inappropriate for them to blurt out over twitter their conclusions on cases they're currently hearing or might someday hear. It probably wouldn't be great for them to engage in ideological or personal flame wars online.
However, if they were able to reasonably understand twitter or facebook and use them accordingly there shouldn't be a problem. For instance monitoring breaking news by watching people tweet in real time but not tweeting yourself, as described in the video, is perfectly acceptable. Additionally they could tweet so long as they realize everything they say is public and being watched closely.
As with most technology it's the way you use it that is really important. If a justice properly understands what twitter is and how it works there is no reason they can't join in. I'd follow them.