Facepalm
From lurkmore wiki
The original facepalm was of a man making the headsigh/facepalm gesture. Text associated with the macro was "Aww jeez, not this shit again". Later, Captain Picard was used to create the Headsigh ASCII and the associated macro that the ASCII was created from.
This facepalm image is used to denote disbelief at dumb comments or exasperating things done by another poster as if to say, "Oh God, not this again."
Related articles
Facepalm ASCII
............................................________ ....................................,.-‘”...................``~., .............................,.-”...................................“-., .........................,/...............................................”:, .....................,?......................................................\, .................../...........................................................,} ................./......................................................,:`^`..} .............../...................................................,:”........./ ..............?.....__.........................................:`.........../ ............./__.(.....“~-,_..............................,:`........../ .........../(_....”~,_........“~,_....................,:`........_/ ..........{.._$;_......”=,_.......“-,_.......,.-~-,},.~”;/....} ...........((.....*~_.......”=-._......“;,,./`..../”............../ ...,,,___.\`~,......“~.,....................`.....}............../ ............(....`=-,,.......`........................(......;_,,-” ............/.`~,......`-...............................\....../\ .............\`~.*-,.....................................|,./.....\,__ ,,_..........}.>-._\...................................|..............`=~-, .....`=~-,_\_......`\,.................................\ ...................`=~-,,.\,...............................\ ................................`:,,...........................`\..............__ .....................................`=-,...................,%`>--==`` ........................................_\..........._,-%.......`\ ...................................,<`.._|_,-&``................`\