Lol -> lul; lols -> luls; lolz -> lulz.
Lulz is the one good reason to do anything, from trolling to vandalism. After every action taken, you must make the epilogic dubious disclaimer: "I did it for the lulz".
This has been pioneered by encyclopedia dramatica, famous for posting a fake craigslist add and then listing the personal info of those who responded.
Why did he post a suicide note on livejournal before killing himself?
I heared he did it for the lulz.
Why post a giant image of 50 Hitlers?
I did it for the lulz.
Lulz... is also a corruption of L.O.L., which stands for laugh out loud. Phil Shuman used this term in a poorly executed last minute piece that was thrown together. It shows his complete lack of ability to perform proper investigative reporting. Many Lulz were generated from this attempt.
"LULZ is a corruption of L O L, which stands for Laugh Out Loud." --Phil Shuman, Fox News