Oh honey I feel for you, I went through the same thing last year. Here was my plan: I asked my son out for lunch (college kids love free food) and swiped his phone during it, then sent myself his student ID. when he found out about it a month later and started yelling at me, naturally I started crying so he calmed down. It ended up as a win win for everyone! I got to make sure he was safe and he got to spend so much time with his mother!