Well, as an earlier article on the Legal Blog Watch Blog shows, even the best of us, judges included, can get carried away with the social networking. There are, of course, the issues of sharing too many of your youthful indiscretions too freely. (I am personally thankful that, even though photos of me--both strangely messianic and less flattering--are freely available online, I came of age in the era before ubiquitous camera phones and Facebook; otherwise I might regret some of my wilder days, or that toga party when I was in law school...) But beyond unseemly photos of your last kegger, there are more complex social networking considerations for lawyers and law students.
The judge who got reprimanded for using Facebook fell into the trap of commenting without enough thought. You see the Judge's Facebook Friend was an attorney who had an active case in front of the judge, and Facebook comments can be ex parte communications; hence, a trial no-no and a reprimand. The judge did some other mis-deeds like Google a litigant and read the litigant's online poetry into the record, but this story is about caution in social networking...
So you might do well to network in the electronic world possibly even finding a judge to be your friend, but you should not leave your reason and ethical considerations at the keyboard.