In Philadelphia, researchers at the University of Pennsylvania find, possessing a gun is strongly associated with getting shot. Since "guns did not protect those who possessed them," they conclude, "people should rethink their possession of guns." This is like noting that possessing a parachute is strongly associated with being injured while jumping from a plane, then concluding that skydivers would be better off unemcumbered by safety equipment designed to slow their descent. "Can this study possibly be as stupid as it sounds?" asks Stewart Baker at Skating on Stilts. Having shelled out $30 for the privilege of reading the entire article, which appears in the November American Journal of Public Health, I can confirm that the answer is yes.
The researchers admit that they didn't look at reverse causation. Which pretty much invalidates their entire study.