So today I posted an article that was published to main page of Slashdot. Good karma.
I checked up on the article, and saw a lively debate. I quickly posted a question, which was short, to the point, and showed that I didn't understand some basic facts in the article I posted. However, it was modded to +5. Ka-ching karma.
I quickly realised my mistake, and posted a reply to myself. This was also modded to + 5.