
I can tell you it does work. I’m working in a lab painted with such stuff. No, we are not doing anything nefarious, but we had developments stints into wireless and radio technology, and having a properly shielded room to work in helps avoiding trouble with the neighbors. I don’t think they would appreciate getting their wifi jammed when someone here is trying to find a bug in a sender or something like this…

“We store the information we collect in secure servers located in the People’s Republic of China”
Now you Americans know how we Europeans feel when Google, Amazon and Facebook store our information on American servers. Hint: The protective wall between Chinese servers and their government are about as good as the one between American servers and their government - at least for non-US citizens. The last thin veil of privacy for Eurpeans has been ripped to shreds by Trump last week.

How about reading the text to the end:
Months after the release of the AirTag, Apple launched the Tracker Detect app for Android phones, where users had to initiate the scan. Google and Apple since have continued working together to make it easier for Android phones to detect unwanted AirTag trackers and for Apple phones to spot Android trackers. Recently, Google rolled out automatic smartphone alerts for unknown Bluetooth trackers, similar to what iPhone owners receive for AirTags.
I was running a server hosting a Gutenberg mirror at home 30+ years ago. And no, it’s not public.