From the other comments here, I think I'm in the minority, but I find this offensive not because of the potential for abuse by the police, but because it legitimates the idea that it's OK to steal from unlocked vehicles. Maybe it's because I'm old and rural, but I'd prefer to live in a society where the societal convention is that "theft is wrong" regardless of whether it requires breaking a window, rather than implying that the victim is to blame for failing to to push a button to properly signify their desire that their belongings not be stolen.

What are the limits to this approach? Should the police break the window and empty the glove compartment, on the theory that windows are easy to break and one shouldn't keep anything valuable in the car? Should the police try out their bump-keys on empty houses, and pro-actively remove the valuables from the 90+% of houses where these work? Should they "kidnap" the kindergartner who is in public without chaperones so that no one else does?

Or should they figure out ways to punish those who break the law rather than those who are obeying it?