Disemvowel comments lets you selectively remove vowels from user comments, if you think they are trolls.
Sooner or later, you will encounter trolls in your blog comments whose only purpose it is to get on your nerves. Instead of deleting those comments, why not having some fun with them?
This plugin provides a link under every comment to remove every vowel and therefore expose the troll to your readers. If you've made a mistake, don't worry, you can get the comment back to normal as well. If desired, an explanatory link can be shown as well.