to be thoroughly demolished online by one of unassailable with and logic, especially when skewered by the weakness of one's own argument. To be malboned is to cede the last word unless you are totally dense or totally masochisitc.
Malboning almost exclusively occurs left malboning right, esp when the right is neocon or tea party-ish. I've never seen it go the other way.
"He just started a debate with Stacy M and has no idea wtf he is talking about? He's gonna get Malboned!"