Ex's Family Keeps Taking Pictures Of New Husband In Public

My friend went through a pretty nasty breakup after being in an extremely toxic relationship for almost 10 years. In the past year she has met a new man and he is above and beyond so good for her and her kids. However... whenever he is picking up the kids from school, a member of the ex's family takes pictures of him at the school. Which, whatever, talk your smack amongst yourselves or whatever petty stupid stuff you have to tell yourselves to make you sleep at night.

However, this evening, he was at the store with one of the kids because mom was home with the other child who was sick. They ran into a friend of the ex's new girlfriend (which the girlfriend was a catalyst for a lot of the drama that happened pre and post-breakup) and the friend took a picture of her husband AND her kid in the store.

Now, I know public places are fair game for photos, blah blah blah. However, now we're taking pictures of minors in public??? At what point does this behavior become harrassment?