Have you ever ended a long lasting friendship, but made the mistake of keeping in contact with him/her via Facebook or telephone?

I’m having this problem right now. My friend, who suffers from Aspergers syndrome, went through a period of drug abuse and stealing from friends and family. After three years, he’s clean and has a steady job. I recently created a new Facebook, and I’m really tempted to send a friend request or call him, just to see how he’s doing. But I know deep down that I should just move on. Have you ever been in this situation? What did you do?