Disturbing images like people throwing up? So anything real life that happens would also be considered "disturbing?"
I'm sure there was more, but kids are not as young and innocent as they used to be... you'd be surprised. I don't think we should blame South Park and shows like it for that though; Thats like blaming car accidents on automakers, it's the parent's job, not the network.
I actually find some episodes of South Park to be entertaining aswell as thought provoking, the latest episode I saw involved Cartman becoming the morning announcer for the school and going off on the school president (Wendy) about how horrible things were in the school. This episode reminded me of Glenn Beck and how the episode progressed was entertaining while showing a not so different comparison to what Cartman was doing and what Glenn Beck has done.
I don't see what the big deal is really...