The new EdCol touches on a number of ways coaches can communicate with prospects via social networks, but the key bit of info is near the bottom:
"Accordingly, although it is permissible for a prospective student-athlete's name and/or picture to appear on an athletics department staff member's profile page of a social networking Web site to identify the prospective student-athlete as a "friend" of the athletics department staff member, staff members may not initiate or accept such requests until such time that it is permissible to send electronically transmitted correspondence to a prospective student-athlete."
So if a coach sends a friend request to a prospect and that request generates an email, the PSA better be old enough to receive it.