The new version of Windows is about to come out, and one of the (optional) features in Windows Vista is speech recognition in the OS to handle certain tasks. But it turns out that a webpage or audio file could be used to trigger the voice commands even if you didn't intend them to, allowing a website to delete your files by playing commands from your speaker that get picked up by the microphone. Of course you would have to have speakers and a microphone for this to work, as well as enabling the voice commands.