I have seen a particular user here (with ~500 reputation). He seems arrogant, down votes other's questions, uses dis-respectful language, etc.? What should be done to such users?
What should be done to these users?
Nothing special that you should be concerned with. Instead, you should take appropriate action case-by-case, considering the item itself rather than the user, just as you normally would. For example:
- If you see an extremely rude/offensive post, edit it if its salvageable, flag it if not.
- If you see a rude/offensive/non-constructive comment, flag it.
- If somebody is actually threatening you then, by all means, either raise a custom flag on one of their posts and explain the situation, or use the "Contact Us" form down at the bottom of every page.
Moderators have the tools to monitor and deal with truly problematic users, so this is nothing you have to worry about, you just have to keep on doing your usual thing. For voting, serial up/down voting is detected by the system and dealt with accordingly without really needing your intervention.
Some things you generally do not want to do are:
- Argue with them in comments.
- Get stuck in edit rollback wars.
- Downvote their posts out of "revenge".
- Call them out publicly on metas.
Just flag and move on (but note that arrogance alone, while it can be irritating, is not flaggable in itself; non-constructive, rude, offensive, and threatening things, however, are).
You'll also want to remember to not take such things personally, which can help you deal with those kinds of situations a little more smoothly.