And, of course many, many said similar things about AirBnB -- "couldn't a thief just book a room for the night and then make off with the TV?" -- and that's proven not to be much of an issue in practice.
Maybe TheSkeptic (brand new account) is a competitor?
Ugh, that's a shitty attitude. I think one of the good things about HN is that people here usually give each other the benefit of the doubt and assume good intentions. Lobbing accusations of bias around are a good way to kill that friendly tone. Unless you've got actual proof of bias perhaps you could keep your accusations to yourself next time?
I think it is also pretty shitty to use throwaway accounts without disclosure and a reason.
Professional thieves are a different matter. Traditional rental agencies have cameras at the rental counter, and get a copy of a driver's license. Building LoJack into the carkit won't work because it is too easy to block a GPS signal with tin foil. The only realistic way to stop professional thieves is to get driver's license numbers and review driving records for all members (which is what ZipCar does).