Please read this on Wired and you might just begin to understand the MML culture.
A present-tense equivalent to the hacker insult, pwned, this geek-slang declaration of victory means, "Guess what? I'm humiliating you and you don't even know it." Legend has it that the phrase was coined in 2004, when one networked gamer sent another the message, "im in ur base killin ur d00dz." (In reality, he used different syntax.) The sentiment lends itself to a variety of circumstances, leading to variations (often featuring cats) such as "Im in ur fridge eatin your f00dz" and "Im in ur quantum box... maybe."