Children should 100% be off limits. It's disgusting, if you ever happen to watch a pap video around kids, and they actually try talking to these celebs' children
Björk always gets painted as a nutjob for attacking that one reporter years ago, but she totally deserved it. The woman was stalking Björk everywhere she went, kept trying to taunt her son, and that was the last straw.
Not all of them are too bad, though. It depends on the celebrity. The ones who have been in the business for a long time and have generally boring lives (eg. Gwen, who has been doing this for almost 20 years now and keeps it pretty classy) literally have the same paparazzi following them everywhere and staying sort of polite, even familiar. I get the feeling that the same few guys wake up every day, drive over to Gwen's neighborhood, and then just wait till she leaves to follow her to Kingston's school, the nail salon, etc
But then you have celebs like Bieber where the paps purposely taunt them, gross.