Is it the ultimate in convenience, or a terrifying glimpse into the future? Three Square Market (32M), a Wisconsin company, has become the first business in the U.S. to implant microchips into its employees’ bodies. The rice-sized chips, called RFIDs (Radio Frequency Identification), are inserted under the skin of the hand. Employees who get the optional implants can enter the building, buy from the company’s cafeteria, and use machinery with a wave of the hand, eliminating the need for ID cards or money. 32M’s CEO thinks people will eventually use RFID chips to pay for everything from groceries to bus fares. But not everyone’s convinced. Privacy advocates worry the chips could be used to track our movements and could harm our health. Says Matthew Feeney, a privacy expert at the Cato Institute in Washington, D.C., a think tank that pushes for individual rights: “This is people sacrificing their privacy on the altar of convenience.”