The esp32 supports efuses that can be used to require a signed binary to boot. So they could lock their hardware to only work with their binary. Source code wouldn’t matter.

Of course if the source is open you can buy and put together your own hardware and then put their code on it.

I’m not advocating what they’re doing. Rent seeking is rent seeking even if they need to recoup development costs. I’d rather pay for open hardware and software with no monthly fee.

Besides all the other arguments, fingerprints aren’t like the movies. You need a reasonably flat surface to get a fingerprint from.

Getting a fingerprint from a house or a car to prove that someone was there at some point, any time in the past, is possible. Getting a fingerprint from a plastic baggy to prove someone held it would be much harder.

The distortions would make it extremely hard to match against a database. If they compare it to you then it might show a match, so if you’re a suspect they might make a direct comparison. If they compare it to the cop? Remember the cop is innocent until proven guilty, so they can’t compel them to give fingerprints for comparison. Yes, they could be in a database, but remember the distortion makes it hard to automatically find this.

Any lab work has a cost, and police are lazy. They aren’t going to spend time or money trying to solve a case. They go with best effort.

Is the list if 40k apps public? Can someone write an app that checks to see if any of them are installed on a phone?