Do off-duty cops have a right to mount surveillance on a neighbor?

Answer 1

They only do that if they're some kinda obsessed creeps.

Answer 2

In general, yes, if they don't use Police contacts/resources.

Answer 3

That depends on the laws in the State where it takes place.  In Georgia, a private citizen is almost like a police officer.

Answer 4

Yes, but not on their property and not in their bathrooms.  The neighbors are entitled to privacy in their home.