Illeeeeegaaaaal

So in the rules and in the Report thingy they mention you can report shit for being illegal. Out of curiosity: what actually constitutes "illegal"? What can possibly be posted that can be reported for illegal content?

Just something that popped into my head. I've never seen somebody complain of illegal banning (probably because it was a permaban?) or probably because nobody is actually dumb enough to post illegal stuff.

why do some post CP and some wipe their disks and fear their house raided for one picture? where do the posters get their guts?