- You can try to resolve the problem with them like a mature adult.

- If they have broken a site rule, please use the 'Report Post' feature in the post.

- You can choose to not see their posts by visiting their profile and clicking on 'Block Member'

If you choose to ignore this advice, be advised that you may be punched and/or banned.

What you should NOT do is personally attack them, gang up on them, harass them or otherwise act like an ass.

Note that the Terms of Service has been changed to specifically forbid making personal attacks or abusive posts against any other member

Read here for more advice