The expression "Don't feed the trolls" is a slang term that aims to keep people from communicating with a person who is deliberately trying to incite chaos and cause a disruption when using various online outlets, such as message boards and forums.

A troll, in Internet lingo, is a person who tries to instigate arguments and chaos by posting and leaving inflammatory comments or messages or otherwise disrupting online discussions. The expression "Don't feed the trolls" means that participants should ignore the obviously inflammatory comments posted by the troll, since their only purpose is to disrupt otherwise normal forum communications.