feedbomb

The act of posting or commenting on an unflattering Facebook photo, usually resulting in its broadcast across the News Feeds of mutual friends and subsequent spread across Facebook. This is typically done with the intent to harm, defame and/or embarrass the individuals depicted in said photo.

When someone you thought was cool likes something bigoted, ignorant or otherwise heinous on Facebook and you see it in your feed, so you start liking as many things as possible that refute said heinous like, hoping the once-cool person will see your likes in his/her feed and perhaps take a moment to consider whether he/she might in fact be a thoughtless moron.