Last week, gracious youngsters from Google, Inc. were stationed below 14th Street, handing cards to commuters. The cards confirmed that those wireless signal bars appearing on certain subway platforms weren’t phishing expeditions by identity thieves or digital phantoms. Rather, they were the fruit borne of a partnership between Google and a wireless Internet provider named Boingo. Log in to their hotspot and get a summer of free Wi-Fi access all over New York City. In return, Google gets to hoard the information they generate, assembling an accurate picture of who exactly was passing through the station and when.