Talk about irony. According to a study conducted at Johns Hopkins School of Medicine, hands-free faucets have a significantly higher chance of playing home to bacteria like Legionella spp., which causes Legionnaire's Disease.
The reason is hands-free faucets have more components than traditional ones, and bacteria was found to thrive in these parts in particular.
The findings fly in the face of why hands-free faucets are popular, and in one isolated case they've actually caused the esteemed Johns Hopkins University to remove them from their clinical areas.
As far as everyday use in public restrooms countrywide is concerned, everyone can keep waving their hands under these magical faucets without worry. The Johns Hopkins officials have assured everyone that we plebeians have little to worry about—it's the clinics and other sterile environments that need to take notice. [WebMD via Geekosystem]