RationalWiki:Leaving and never coming back
Leaving and never coming back is an internet euphemism whereby a frustrated participant in a forum, or blog, or whatever, takes away their ball and refuses to play. Sometimes this occurs after grandly declaring "victory," but more often when they are unable to get their own way. Oftentimes, the LANCBer cannot get his or her way because the forum is riddled with sycophants who gang up on them, even though the LANCBer is clearly correct.
It is usually publicly announced, done with great fanfare, and followed by a quiet return within a week or even within a few minutes. A statement of LANCB virtually guarantees a return, thus destroying any ultimata or idealism involved in their "leaving."
A particularly grandiose LANCB is often referred to as a flounce. The word can also be a verb, as in "Tyranny_of_Evil_Women flounced out of the forum, but he was back three days later posting as AgentLemon." If accompanied by a particularly emotional farewell speech, this is also known as a Grand Staircase Exit.
It is a common affliction with internet users who are in urgent need of the wahmbulance.