Coaches have realized that every kid regularly checks their social media platforms. Its a given that it has taken over mail as a faster and easier form of communication. So as the times have changed so have the coaches. Most every big time Div. 1 coach has a twitter account, where they reach out to top targets, engage the fans, and also regulate the activity of the players that they are recruiting.
High school kids are bound to do something stupid, and most times coaches aren't going to pull a scholarship for making a mistake or two, but when they see a systematic problem in a kid, it is hard for them to take a chance on offering them a scholarship worth a ton of money. Players with pictures of underage drinking, weapons, or drug paraphernalia are likely to be under heavy scrutiny or even potentially have their offer pulled.
Another aspect of recruiting on social media, is the presence of recruiting analyst. Or team pages where commitments are discussed and analyzed by the followers that they have. This allows fans to be involved in the recruiting process, keeping up to date with current an potential commits. With this comes the opportunity for added hype, or criticism of a recruit. Example: Jacob Eason, who has become a God to Georgia fans, after videos of his high school games surfaced on social media. Played can either be harmed or helped by the hype surrounding social media, and hopefully in the case of Eason, the fans assessment of Eason is accurate (if not an undervaluation).
With todays social media movement, it is easier for players to get noticed by college coaches, easier for them to interact with these coaches, but they can also come under heavier scrutiny and surveillance at the same time. After assessing the pros and cons of the social media among potential college recruits I believe that they would be better off keeping the majority of their affairs to themselves. Allowing them to live lives separate from their countless followers, so that the pressure does not become too much, and so that they are able to live (somewhat) as normal college aged kids.