From the why-kids-need-to-understand-natural-selection department: Antibacterial Products May Do More Harm Than Good.
Unlike these traditional cleaners, antibacterial products leave surface residues, creating conditions that may foster the development of resistant bacteria, Levy notes. For example, after spraying and wiping an antibacterial cleaner over a kitchen counter, active chemicals linger behind and continue to kill bacteria, but not necessarily all of them.
When a bacterial population is placed under a stressor – such as an antibacterial chemical – a small subpopulation armed with special defense mechanisms can develop. These lineages survive and reproduce as their weaker relatives perish. “What doesn’t kill you makes you stronger” is the governing maxim here, as antibacterial chemicals select for bacteria that endure their presence.
Blatantly stolen from BoingBoing.