Physical Danger
Parole officers lead pretty dangerous lives. Parolees aren't always excited about having to report to their parole officer, especially if they want to pick up where they left off in their criminal career. Moreover, parole officers generally work alone. Handling a violent criminal without any backup is no day at the park. Sometimes it's not even a day at the dentist.
Officers may find themselves working in a small town where it's hard to keep their own identity or home address secret. To keep their families safe, many parole officers don't form personal attachments or reveal any personal information with their parolees. Not even their favorite color. You never know when that little tidbit is going to come back to haunt you.