This behaviour is a thousandfold worse when you have kids, especially at social gatherings like birthday parties. Other parents (at least in my age cohort) assume it is OK to film them and post it to whatever social media they have without even asking.
Here in Germany we are about to start our daughter in pre-school ("kita") and every single parent had to fill out a few forms explicitly stating if they were ok or not ok with having photos or videos taken of their child (both by staff and by other parents).
