NCAA bylaw 13.4.1.2 states that prospective student-athletes may be contacted via e-mail or fax, but that "all other forms of electronically transmitted correspondence (e.g. Instant Messenger, text messaging) are prohibited." That means a coach may promote the school's programs and reputation, but cannot individually contact a player or any individual associated with that player through electronic media.
Per LSU's student paper, The Daily Reveille, NCAA associate director for public and media relations Cameron Schuh confirmed in an email that "as long as coaches are not using Twitter to contact individual prospective student-athletes," that there is "no issue."
As seen in the Tweets below from several SEC and NCAA football coaches populating the Twitterverse, there is a wide array of subject matters, none coming close to being in direct contact with recruits:
CoachSark (University of Washington) @BarackObama congratulations on your 100 first days. Watching for you live here on CNN. MarkRicht (University of Georgia) Here is all the information for this year's Mark Richt Football Camp... http://markricht.com/blog/blog.php LaneKiffinUT (University of Tennessee) Slow day in the office...great time to watch some film... Play4brew (University of Minnesota) 2009 Gopher Football Captains are, on offense Eric Decker and Adam Weber on D Lee Campbell Eric Small Garret Brown and Simoni Lawrence!! LSUCoachMiles (Louisiana State University) Smacker finishes ahead, eating at voodoo bbq, missing manny and mom who are playing giants baseball in Memphis! UM_CoachRod (University of Michigan) Congrats to our 4 Seniors that will graduate today and attend grad school next fall!! Great job David, Zoltan, Jason & Tim! JayPaterno (Asst. at Penn State) http://twitpic.com/4ep5j - Nike Camp Day today at Penn State. NCAA Rules prevent us from attending or coaching. PeteCarroll (University of Southern California) Heading down to san clemente for the nike 6.0 lowers pro surfing championships... Wish I could catch some waves like these guys!