It's getting harder to cover your tracks as even the most everyday activities -- from running a Google search to using the E-Z Pass lane -- leave a lengthy digital trail. Ever get the feeling that someone's eyeballing you? You're probably right. These days, between the news that the National Security Agency has been eavesdropping without warrants and that the Justice Department wants to know what searches have been conducted on Google and elsewhere, it's no wonder you feel under watch. The real surprise, though, may be how so much of what you do on an everyday basis already gets screened, monitored, tracked, scanned and observed - often without your ever knowing it. From spyware on your computer to police cameras on your street to GPS devices on your cell phone, how much of your private life is really private any more? "It's all part of the general evaporation of privacy," said Peter Wayner, a Baltimore-based computer programmer who has written se...