Trolls were once thought of as mythical creatures, but they are now very real. If you've spent any time interacting (or reading) comments on the Internet, you've undoubtedly come across trolls.
Troll is a slang term for people who purposely sow discord and aim at getting people upset. They often do so anonymously or under a pseudonym, avoiding the personal criticism of others by hiding their identity. Internet Trolls, while annoying, are relatively harmless when they are recognized for what they are - instigators and curmudgeons. They can even be beneficial to an organization if their comments bring a lot of eyes to a post.