I once went a whole year without ever touching a doorknob. Like many Americans, I was paranoid about the fine patina of pathogenic mutants (e.g. bacteria) that encrusts most surfaces. I even used antibacterial hand gels, figuring that if I killed off the little bastards in biblical numbers, my own odds might improve. Come cold season, though, I was still wiping sniffles away (albeit with chapped, medicinal-smelling hands.) A recent report from Columbia University reaches the same conclusion I came to that miserable winter— using products with antibacterial properties can't keep you from ever getting sick. In fact, they may actually do more harm than good. The year-long study found that households that use antibacterial cleaning products are just as prone to sickness as those who don't. Why? Viruses, not bacteria, are responsible for most common infections and antibacterial agents don't kill viruses. Plus, when you scrub down your kitchen with sanitizing products, you're really just wiping out the weakest 99 percent of bacteria. This eliminates competition among the strongest strains and pushes them into a dominant position, where they're free to have wild microscopic orgies long into the night. Before long you've got a few trillion "superbacteria" that are harder to kill than a crypt full of zombies. So play it safe and only bring out the big guns when you have to— or else Bruce Campbell will kick your ass.