Professor Joe Blitzstein uses Twitter to share articles and other tidbits with his students in Statistics 110. Joe uses @stat110 to share articles that touch on statistics and probability. Rather than email every link to the class, this is a way to provide optional supplementary information to those that desire it. While some students in Stats 110 follow Joe, he also has many followers that watch the iTunes U lectures and use this forum to ask Joe questions.
Check out his twitter page here: https://twitter.com/stat110