Say a probation officer wants info about people you know... do they have any right to share information about why he/she is on probation? Would that be a violation?

Your question is unclear. Are you on probation and your PO is pumping people you know for information about you? Or are you being pumped about info on someone you know who happens to be on probation? I believe that it is legal for a PO to indicate to others why you're on probation, even if it isn't obvious why (s)he would. If a PO is trying to get information from you or share information with you about someone else and you feel uncomfortable about it, I believe that you are under no obligation to talk with them.