[rdl]

If it were a company sponsored hackathon, I'd probably just pay for the laptop. Probably wouldn't publicize the whole thing, and if it happened a second time, would seriously re-evaluate security.

A school or community hackathon is a much more ambiguous situation. Get a police report, and see if you have event insurance or something to cover it.

I never leave stuff unattended in public, but things like hackerspaces, YC's office, etc. feel different. I do screenlock always, but I can't say I'd never leave a machine unattended in a semi-public environment.