Also don't forget that at an event that size outsiders could potentially get in or maybe some staff/security did it. Best bet is to think about it as being a c

Also don't forget that at an event that size outsiders could potentially get in or maybe some staff/security did it. Best bet is to think about it as being a completely public place at that point. Would you leave your laptop unattended at the corner of a busy street? Hopefully the laptop ends up being misplaced or reported to lost&found and the organizers just don't know about it yet.