AI uses memes to control people. Part of a number of stories by John Barnes? One story has a bunch of meme-controlled mercenaries who capture a girls' school and 'serb' and kill all the residents. Read it back in the 00s.
Almost certainly this is one of the Meme Wars series of books by John Barnes. Your description doesn't actually give enough info to positively identify which of the books it is, but it's most likely to be Kaleidoscope Century. The protagonist talks about seizing a sorority house in the name of its meme deity and proceeding to rape (or "serb") the prettiest girls.
That had been fun; Fargo Dome hadn’t been hit significantly before, and the loot was terrific. Not to mention Sadi and I had grabbed one whole sorority house at the University of North Dakota, turned the ugly ones over to One True and spent three days serbing the pretty ones before Murphy called the unit back in and we had to hang all of them.