What website will record my webcam and save it automatically?

I use my laptop at the library all the time, but sometimes I have to use the bathroom. Unplugging my laptop and bringing it with me is a problem (long story but technical problems with my laptop). So is there any website that lets you record things for like 5 minutes on your webcam, and saves a record of it if the laptop is turned off? Like I want any thief who approaches my laptop to see themselves on webcam, and if they snatch my laptop, that video of them walking up to it is saved somewhere on the internet, even if the laptop is unplugged and no save button is pressed to save it. Anything like that? I already have a program (Prey) that takes a picture of them while they use it, but that's hidden and isn't much of a deterrent.