What kind of rights does my son's father have if he was incarcerated?

..including changing my number? would that affect me if he took me to court? I also wanted to mention that earlier this year when i mentioned he should be glad I don't have him on child support b/c I really have made it so easy for him...his response was that i wouldn't ever think about doing that b/c i would be the one hurting....he told me to take it how i wanted to. Should that scare me?