In reference to players of MMORPG's that instead of taking a break to go to the bathroom, they take off their sock, defecate in it, and throw it aside for later disposal. Refers to someone who stays up all day and all night to play an MMORPG.
"Steve, how'd you make lvl 50 already? You were just lvl 45 a couple days ago. You friggin poopsocker!"
A person who is so engrossed in their MMORPG (World of WarCraft, EverQuest, etc.) that they forgo even the most basic formalities surrounding biological need, like going to the bathroom to defecate.
They poop in a sock instead.
Stop being a poop socker and come out to the bar.