According to https://math.stackexchange.com/users/54911/twiceler?tab=profile, this guy has 6863 reputation, but he answered a question with 756 upvotes with a +400 bounty. That should warrant him at least 7000 reputation, but the information proves otherwise. How?
It has been more or less answered in the comment. To be more precise, you can visit their activity page and see that they got around 200 reputation for four straight days, starting at May 3 '13. If you click on each day, you can see that the "events" are counted 119, 71, 30 and 27 respectively. If you click the "events", you will see that, because the rep cap, some upvotes correspond to no reputation.