With the news of Lincoln Riley leaving Oklahoma and taking the USC job, and also rumors that Caleb Williams goes with him, what’s to stop coaches from accepting a different college HC position and taking 5,10,15 whatever the number of players to their new job?  Obviously, available scholarships (and we know how these coaches can manipulate the numbers), could be a hurdle, but this could get wild.  
I don’t know how blindsided the Oklahoma administration was, but the fans and players certainly were.  I don’t think Riley could have screwed over Oklahoma any harder if he tried.  
What’s to stop it happening here or anywhere?