You almost have proven your point about it all being a matter of opinion about the degree of which it is ethical to troll via posting family photos.
You are in the clear as long as what you are doing isn't a breach of the Code of Conduct which states:
Harassment includes offensive comments (related to gender, race, sexual
orientation, disability, appearance, or religion), posting or display of sexual
images, deliberate intimidation, stalking, public release of private information
He does have his info on FB, it is set to public, could what you're doing be considered stalking online? I'm on the fence here, but maybe others could weigh in, because I really think it is messed up search for him on Facebook and put his family on here like that and if what you are doing could be considered stalking then hopefully it won't be allowed.(edited)