Do not touch that computer. It is a biohazard (theregister.com)

I encountered many of these tar covered PCs doing retail computer repair. One of the worst I can remember was a wood shop PC of a heavy smoker. The combination of tar and sawdust absolutely glued everything in place. Dead mice and roaches were common. However, the only computer I remember saying we wouldn't touch was a slim desktop where someone had vomited into the vent on the top.