For anyone who's curious, the closest equivalent in the US is P25[1] or "Project 25". And if you're wondering, yes, P25 systems have been known to have their own share of vulnerabilities of various sorts. My favorite one[2] is the one that lets an attacker force a P25 radio to broadcast tokens "on demand" allow you to (theoretically, with the right receiving setup and software) track the location of P25 radios more or less in real-time.
And on a related note, for anyone who is interested in listening in on any local P25 transmissions, you can do so in a fairly inexpensive manner, using an RTL-SDR dongle and the Open Source op25[3] software package. No listening to encrypted traffic, but IME, many (maybe most) public safety agencies keep most of their traffic in the clear. More so for fire/ems traffic. Law enforcement is more likely to be encrypted, but even then, I find that many jurisdictions only encrypt a small number of channels, like maybe a dedicated vice/narc squad channel, SWAT team channel, etc. General LE dispatch and tac channels are still in the clear in many areas.
It's an active attack (requires you to transmit traffic to trick the radio into sending the response beacons) so at the very least you'd almost certainly be in violation of some FCC regs. So the charge might not be "tracking law enforcement" but rather would be "illegally transmitting on a public safety frequency without a license" or something along those lines. And if somebody got caught doing this, I'm reasonably sure they'd find a way to pile on a few more charges as well.
And note that since it is an active attack that requires the attacker to transmit, it opens up the possibility of the attacker giving up their own location in turn.
My take is that it's fun to think about, but largely lacking in real world applicability in most situations.
Transmitting on spectrum you don't have a license for- especially when the government WILL cast it as "interfering with emergency services" or just Big-T- very much is.
And on a related note, for anyone who is interested in listening in on any local P25 transmissions, you can do so in a fairly inexpensive manner, using an RTL-SDR dongle and the Open Source op25[3] software package. No listening to encrypted traffic, but IME, many (maybe most) public safety agencies keep most of their traffic in the clear. More so for fire/ems traffic. Law enforcement is more likely to be encrypted, but even then, I find that many jurisdictions only encrypt a small number of channels, like maybe a dedicated vice/narc squad channel, SWAT team channel, etc. General LE dispatch and tac channels are still in the clear in many areas.
[1]: https://en.wikipedia.org/wiki/Project_25
[2]: https://www.reddit.com/r/tacticalgear/comments/1f4d5dr/psa_p...
[3]: https://github.com/boatbod/op25