Some people seem to create a new account for each story they comment on so they or their comments can't be 'tracked' between stories.

I create a new account for each different topic I comment in so that only dang can track me. ;) For real though, I would have -1,000 karma if I only used one account because apparently to other HNers think that my comments and questions are pathetic. Very elitist community, I feel safer making new accounts.