Comment Murder 

When someone randomly comments on one of your facebook posts, making everyone else not want to.
Usually a relative or a lesser-liked friend of yours, or someone that you don't like that is a friend of yours on facebook.

John Doe is gonna go 2 da baseball game!!
Grandma Doe - Hey sweety!! How are you? Say hi to your mother for me!

John (mentally): Oh god, Grandma just performed comment murder!

Comment Murder by lochei May 15, 2010

Comment Murderer 

One who comments on a facebook status with a random word, or stupid joke that no one understands or everyone hates, therefore causing other people the sudden urge not to comment on it. Usually this person is not liked by anyone on facebook, and in most cases real life.

Also see comment murder

Person 1 (Joe just posted "asdfhsadf" on my status.)

Person 2 (Wow he's such a friggen comment murderer)

Comment Murderer by ChAoS x DaRk April 9, 2011