Yes. He uses sockpuppets for voting, so presumably he uses them for upvoting himself as well. But most comments of his that I have seen I would expect to have positive (1 or 2) karma from anyone else as well, and if his comments were sufficiently horrible people would downvote him enough to overwhelm any amount of sockpuppets.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.