Market turmoil makes it too easy to justify selling any stock these days. While individual investors never profit from their own panic, it is a good idea to play devil's advocate with investments.

Consider oil-linked fund United States Oil (NYSE:USO). Though oil still anchors our energy economy, you'll find that a few of the 1,279 Motley Fool CAPS members weighing in on the investment offer reasons to be bearish.

Here at The Motley Fool, we like to consider both the good and bad sides of an investment. Below I've highlighted three of the main bearish arguments on United States Oil. Be sure to read the bullish side as well, and then weigh in with your own comments below or rate United States Oil in CAPS.                                            

1. OPEC influence
OPEC may increase output in an attempt to keep oil prices between $75 and $80 a barrel, according to the organization's secretary-general. (Its members produce about 40% of the global oil supply.) OPEC says prices are in a comfortable zone right now, and one JPMorgan Chase analyst says that there's a big incentive to keep prices from going too high, in order to keep sectors like transportation dependent on black gold.

2. Peak gas
Although the International Energy Agency recently forecast higher global oil consumption next year, compared with a weaker 2009, some experts believe that the developed world passed the point of peak oil consumption several years ago. And ExxonMobil's (NYSE:XOM) CEO recently said that peak demand for gasoline has come and gone, as car companies like Ford (NYSE:F) focus on more fuel-efficient vehicles.   

3. Alternative fuels
Between T. Boone Pickens and gas producers like Chesapeake Energy (NYSE:CHK) pushing for more natural gas vehicles and major energy companies like ExxonMobil, Chevron (NYSE:CVX), BP (NYSE:BP), and Valero (NYSE:VLO) taking an interest in next-generation alternative fuels, some investors see several threats to the long-standing dependence on oil.

To see more details of what CAPS members are saying now about United States Oil, just click on over to Motley Fool CAPS and have a look -- or add your own thoughts directly to this story in the comments box below. And get a rundown of the bullish argument here.