The cameras that they have to read plates in a lot of different conditions and various states of cleanliness. Some states allow O and some states allow 0, and some states don't care. Combine the two issues and cops get lazy and want to check the plate with both the 0 and O just to "make sure".

The cameras also confuse D and Q with 0 and O. And 5 & S, and 2 & Z, and 6 & G, and 8 & B.

The cops have likely been doing this for decades, because the human eyeball can confuse an O for a 0 much worse than image recognition does these days.

Or at least, enforce a totally unambiguous font, like slashed zero!

Doesn't solve the issue until all 48/50 states have the same standard.

interesting. i never new a fraction of something could be considered all.

I think the assumption is most criminals won't bother to bring cars from Hawaii or Alaska if they don't follow along.

Yeah Alaska plates are fairly rare so you could maybe get away with them not adopting the standard. Hawaii plates are EXTREMELY rare because of the cost of freighting a car over and there's no real reason to register a car in Hawaii that I'm aware of. [0]

[0] I'm thinking here of places like Montana which attracts a fair number of out of state registrations to avoid sales and registration taxes in some states. PS don't try this most states already consider this and you're often violating the sales tax laws if the car doesn't leave the state within a few days of purchase.