Spill your morning coffee on your MacBook and then take it in for covered warranty service? Those days are ending; water damage is obviously a violation of the AppleCare warranty, and the new MacBook and MacBook Pro computers, introduced last week, include what cellphones have had for years: Liquid Submersion Indicators, which alert technicians to water damage. Located under the keyboard and near the trackpad, the sensors change color when exposed to a liquid. Once these sensors are activated, there is no way to undo the process, so you’re just gonna have to fess up next time, so please - no more Shirley Temples near the hardware, okay?