Wonder why movies weren't mentioned?
My guess would be that movies have 'ratings' for their intended viewing audience. It's sort of hard to go after a rated 'R' movie for having certain content, when the rating is there for having that content in the first place. If you don't want your family seeing that content, then don't buy rated 'R' movies for them. Same goes for video games, which Wal-Mart also sells, and it doesn't seem like they're being attacked either. I'm sure there's more 'shoot 'em up' video games at Walmart than 'high cap mags.'
Music, OTOH usually doesn't have such ratings. Sometimes they will have an "explicit content" warning, but it's much easier to go after music, because it generally doesn't have these ratings in place. I don't think there's an age limit, when buying music. You don't need to be 18+ to buy a hip hop CD, while you generally do need to have ID to purchase 'M' rated games, and 'R' rated movies. If they added the same rating to music, I'm sure this group would have nothing to whine about, because minors wouldn't be able to purchase this music, and parents can choose whether or not to buy this music for their families. I don't agree with what they're doing, but this is my opinion for why they chose to attack what they did, and didn't attack anything else. The whole thing is silly to me. Why do groups feel like they have to protect the masses? No one is forcing any of this stuff into people's hands, they can choose whether or not to buy this 'sexy music' and Wal-mart or any other place is doing nothing wrong by selling it.
Also what counts as 'sexy music' does it have to lyrics that depict sex, or does Smooth Jazz, and saxophone music count? That music sounds pretty 'sexy' to my ears.