Chris Grace, an ironworker from suburban Chicago, is a Duke fan. A mural in his basement bears the likenesses of the former stars Christian Laettner, Bobby Hurley and Grant Hill, and he regularly checks websites to learn which high school basketball players the Blue Devils are recruiting. Then Grace goes a step further: He sends recruits a friend request on Facebook.

"If they accept my friend request, I'll send them a message telling them how great it would be if they'd commit to Duke," said Grace, 30, whose father attended the university. "They don't usually respond, but I think it helps a bit. But if they don't commit to Duke, I unfriend them."

Grace said he saw nothing wrong with using social media platforms like Facebook and Twitter to reach out to some of the best high school players in the country, as long as there is no harassment. And he is far from alone in doing so. But what Grace and other fans like him may not know was that he had been violating NCAA regulations.

The NCAA allows coaches to correspond with recruits via email, fax and social networking sites. But since 2007, it has prohibited all other forms of electronically transmitted correspondence, including text messaging, instant messaging and posting messages on a user's Facebook wall. Alumni, fans and boosters, individually or in organized groups, are not permitted to contact a recruit for the purpose of enticing him to attend a particular university.

The NCAA would not say whether it had penalized any programs for transgressions by fans using social media, but it said the burden of monitoring and regulating the sites fell to the colleges.

"If a school comes across an instance of this happening, it is expected that they would reach out to those athletics personnel, fans and boosters and reinforce the ground rules related to communicating with recruits," Cameron Schuh, an associate director for public and media relations for the NCAA, said in an email.

College officials argue that there is no practical way to comprehensively monitor an instantaneous medium like Facebook to ensure NCAA compliance. And the public has been busy, with many recruits in high-profile sports like basketball and football being contacted regularly through the Internet by people linked to a program only by their allegiance to it.

Duke fans seem to be particularly active on Facebook. One group, Austin Rivers to Duke, was created to try to woo Rivers, a high school senior from Winter Park, Fla., who is the son of Doc Rivers, the coach of the Boston Celtics. Rivers may be the most visible high school athlete in the nation, with more than 18,000 Facebook fans, more than 23,000 Twitter followers and YouTube highlight clips that have been viewed nearly 1 million times. He has committed to the Blue Devils.

Duke noted that when the basketball star John Wall was in high school, its compliance office asked the creator of the John Wall Come to Duke! group on Facebook to cease and desist. The creator changed the name of the group to Wohn Jall Come to a School in Durham, then deleted direct references to Duke.

Wall eventually landed at Kentucky, played one season and left for the NBA. One Facebook site dedicated to luring him to the Wildcats was called John Wall, I'll Pay You to Come to KU.

Anupam Chander, a University of California-Davis law school professor who writes frequently about social media, said colleges could institute code-of-conduct regulations to discourage their students from contacting recruits but could not infringe on the public's First Amendment rights.

"Schools are asked to comply with NCAA rules, but at the same time, they don't have the power to control the speech of these individuals," he said. "The best claim for any of these schools isn't a legal one, but a moral claim. They can tell fans, look, please don't jeopardize our good standing with the NCAA, but that's as far as they can really go."

For many promising athletes, collecting friends on Facebook and followers on Twitter is a validation of their talent. But the unprecedented level of direct communication with fans can have its drawbacks.

Justin Anderson, one of the nation's top junior basketball players, who attends Montrose Christian School in Rockville, Md., recently shut down his accounts before committing to Maryland because he was being inundated with messages from fans of colleges he was considering.

In February, Cyrus Kouandjio, a 6-foot-7, 305-pound offensive lineman from Maryland, announced his intention to play for Auburn on ESPN, then changed his mind and signed a letter of intent to play for its archrival, Alabama. Not wanting, he said, to "disrespect anyone," Kouandjio accepted all the friend requests he received during his recruitment. His total soared to 5,000, the limit for any personal Facebook account.

Most of the messages he received were supportive, but a few were quite nasty. His wall, he said, became a "civil war" between fans of the two universities.

"Some were just wishing bad luck on me," he said. "That I'd break my leg or have to redshirt my freshman year, stuff like that."

Andre Drummond, a 6-9 center from Oakdale, Conn., whom many recruiting experts rank as the top high school junior in the country, has nearly 3,000 Facebook friends, among them Connecticut's basketball coach, Jim Calhoun, and college players from programs that are recruiting him, including the NBA-bound Kyrie Irving of Duke.

A number of Facebook pages bearing Drummond's name have been set up by others, most carrying pleading missives from fans of North Carolina, Kentucky, Duke and other programs. One of them, Andre Drummond Come to Louisville, has fewer than 60 members, but three are affiliated with the Cardinals: Zach Price and Chane Behanan are top recruits and the other, Rakeem Buckles, is a current player.

It is unclear whether a player's membership in a group constitutes a violation, and the NCAA would not comment on the matter, but it appears that it has not established clear guidelines for players and recruits regarding Facebook groups.

Syracuse fans have tried to exert civic pride to pressure DaJuan Coleman, a coveted basketball recruit from nearby DeWitt, N.Y., to stay local. The group, Supporters for DaJuan Coleman to Stay in Syracuse, had nearly 500 members last month.

Syracuse and Louisville representatives said in e-mail messages that they were unaware of the Facebook groups trying to steer recruits to their universities but indicated that they would ask the creators to take down the pages. Syracuse soon set up a Facebook account with the name Cuse Compliance and posted a note on the Coleman group's Facebook wall asking that it be shut down. Within days, it was.

Despite the concerns about social media sites, many high school and college coaches say Facebook, in particular, is an effective recruiting tool.

"Kids don't check email, they don't take calls and we can't text, so Facebook is useful for us," said Jason Williford, a men's basketball assistant at Virginia.

Chad Millard, a former top basketball recruit who committed to Louisville in 2004 when social media was in its infancy and college programs sent recruits printed literature, said sites like Facebook made the recruiting process more complex for players.

"It would make me a little more nervous to be recruited now," Millard, who later transferred to Creighton, said in a telephone interview. "It would have been flattering to get a friend request from someone like Jim Calhoun, but it's also a little scary because you give people a real inside track on your life."

Blessing or curse, social media sites will probably continue to play a role in the recruiting process, and fans like Chris Grace maintain that trying to sway athletes online is harmless.

"I'm sure some fans message them every day and harass players who commit to other schools, but I don't do that," he said. "I'll hate them during the season. I don't do it on Facebook."