Wtfpwn, v. - To pwn very hard, ostensibly to the point of making the pwnee say "wtf"

Beyond simple a simple pwn, "wtfpwn" means to pwn someone in a quick and decisive manner, such that they don't know what hit them and/or have little chance to react before dying.

To wtf pwn, is to completely and utterly destroy something in style, commonly used by "wtf 1337 cnuts" like fw.