Happy holiday weekend from the Alameda County Sheriff's office! They're already ahead of your Labor Day discount sex-shopping plans. Police answered Craigslist ads in the "erotic services" section and set up appointments in Dublin and Castro Valley hotels, posing to the prostitutes as clients looking for a late-night session. At 2:30 a.m. and 9 a.m. on Wednesday, between both stings, the cops made 57 arrests , the majority for prostitution and "suspicion of aiding or facilitating prostitution."Aiding the cops: their search button. This is one of the bigger busts off Craigslist this year, with two twists: targeting the late-night working girls, and doing it when rent is due and women are more prone to risk using Craigslist, which makes them easy targets for vice cops. For all they want to call their raid a remedy to "cyberpimping," the cop strategy is as old-fashioned as it gets.