I imagine attacking "violent porn" would probably wind up attacking BDSM, and maybe, even animated violence, even though that is probably not what someone is thinking of when saying that.

Also, there was one which coded "taboo themes" (i.e. I guess incest) as "violence", even though it's not really what would come to mind when someone says "violence" either. Also, someone almost certainly doesn't want to go and actually do that...

There was also a researcher who pointed out that anything which could be construed as "violence" would (i.e. spanking) by someone with a bone to grind.