Properly used, "own" (not "owns") is an adjective. For instance, "I want a red car with baby-harp-seal-skin seat covers of my own."
Not, "John rocks. He totally owns."
This is a particularly egregious use of slang that I would like to see stamped out, immediately. I am prepared to use The Most Annoying Noise Ever to enforce my owns-free pogrom.
You have been warned.