If someone is short this stock they want to keep the price down. There are rumors of lots of naked shorting on stocks like this that the SEC turns a blind eye to. Also, if someone wants to take a large position, it's a good way to shake the weak hands out and get stock at a bargain price.

And stupid as this may seem, I once knew a guy who had worked as a junior trader for a market maker. He said they got bored and so instead of playing video games, they would screw around with the small investors. I have experienced putting orders in at the ask only to see the ask move up -- and have this happen several times in succession, only to see the price drop WAY down after the order finally filled. So I have concluded that he's right -- never underestimate the boredom and venality of the humans who work for the market makers.