So an Indiana judicial ethics commission opined in an opinion that was posted on Westlaw:

Rule 2.17 of the Code of Judicial Conduct requires judges to prohibit the broadcast of court proceedings except under a narrow set of exceptions. … The Commission’s view is that microblogging, tweeting, or electronically relaying a written message does not constitute broadcasting under Rule 2.17, unless the transmitted message contains video or audio of court proceedings or a link to videotaped court testimony.

I leave to others the question of whether outright broadcasting of trials should be allowed, but I thought this interpretation of what counts as “broadcast[ing]” in the Twitter age was interesting (and, I think, correct).