WTF

Overview
"WTF", typically followed by one or more question-marks (as in "WTF???"), is a neologism standing for "What The F[rea]k?" (the polite version) and generally indicating stunned incredulity in reaction to some particular item of news. It is most commonly used in internet communications, especially chat and IM, where it approximately translates to "How could anyone with two brain cells to rub together say/do that?"

Links

 * The Daily WTF: An ongoing collection of "WTF" moments, mostly computer-related