The article said that the police 'were able to track the AirTag'. Granted, articles are often wrong (or totally correct), but how could they, the owner, transfer the AirTag to police, or share the identity of it. Did they drive around with the owner in the backseat? It just sounds weird.
Can a third party track an AirTag? People figured out how to track those Nike+ shoe pods years ago. Those things did not broadcast a large signal but I don't know the particulars of them and their capability, even though I had several. (I actually found a new one in the sealed Apple/Nike box. DOH!!
Tracking AirTags? Would a Bluetooth sniffer really be able to track one? I guess I'll have to experiment...
Assuming this is the incident you're referring to. The owner tracked her AirTag and informed the police of its location.
A Pennsylvania woman recovered over 100 political campaign yard signs for Democratic candidates in a dumpster behind a restaurant on Wednesday morning, with some help from an Apple AirTag.
Local police believe a resident had put the tracking device on a sign—perhaps anticipating that it might be stolen—and anonymously called to inform them of its location.