I'm not sure about harming their ego's.
I think many if not the majority of vigilante type anti's are the way they are because they have a kind of fear of being unimportant and so attacking maps is their way of trying to feel important, sort of like people afraid to join the army but instead like to walk around talking as if they're in the army to live out a fantasy safely. It's almost like an extended midlife crisis.
I mean they could join the police but that entails training and danger so instead they single out the one group that's the safest group to target and then go after them, either in person or online. If they get lucky they get to destroy a life and with that comes some bragging rights to others doing the same thing and maybe by doing that they can feel a little less pointless, a little less invisible.
I can't help feeling sorry for them if I'm honest because underneath all that are problems, fear, self hate. I expect if anti's sat down with a psychologist they'd learn a lot about themselves and would find some peace but sadly even that requires a level of bravery they don't have.
Ego is tied up with it all, it's a kind of false ego or rather the desire to have something to have an ego about.
It has also been observed many times that many anti's are also maps themselves, I think that's why they target maps. They have a lot of identity issues deep down, inner conflict and this is their way of dealing with it. Sort of like if they hate on maps then they couldn't possibly be a map but deep down on some level they know they are. If you combine those deep identity issues, inner turmoil, feelings of doubt and unimportance you will end up in a pretty messed up place, messed up enough to actually go out of your way to try to destroy the lives of good people minding their own lives.