What the heck does ctfu mean?

[Emily]

I've saw it on Facebook and have no f**king idea what it means. can someone please tell me?

[Frank]

Calm The F--- Down.

[fainttoad080]

I've wonder that too

[Haley]

it means " cracking the f**k up " .

[Rhoda]

Cut the fuck up

[some guy]

Crack the f*ck up

[Jahangir Khan]

Cracking The Fuck Up.

[Wukong]

Most common -
"Cracking The F*** Up" or "Cheer The F*** Up" When laughing so hard you can hardly breathe. When someone does or says something completly and utterly funny, ridiculous or stupid.

You see it on facebook sometimes.
It's used by people who think it's cool or hip.
But it isn't.