No one is in just one of these groups. The groups I listed are just tendencies I've seen in posting patterns among members of various forums I've visited. People can display posting patterns of several of these groups and sometimes their posting style can vary depending on the forum or the topic. On a more heavily moderated forum, someone might tone it down more than on a forum where 'anything goes.' What I meant when I said someone is in one of these listed groups, refers to their most common style.
I also think the anonymity of the Internet goes to peoples' heads at times. I'm talking mostly about trolls who say things just to get other people worked up. Do these people also act like jerks in real life? Maybe some do but not necessarily to the degree they would on the Internet.