Actully "People Watching" is a hobby. To sit in a park and watch people, observing behavior, take a picture if need be... is not a crime. Now if one of the people asked him to not do it, and he continued or followed them, then thats harrasment.
Just because a couple people think its wierd doesnt = this a guys needs to be taught a lesson for creepyness.
Trust me, there are far worse things that this individual could be doing to deserve a strike.
If he gets a strike, then noone can ever post up a picture of anykind of any person. That could be some picture of someones mom/dad/son/daughter/ that he/she doesnt want others blasting on the net... how likely is that... none to no way in frozen hell.
Get a grip guys, theyre just pictures.