[Its_Padar]

If it functions exactly as an AirTag does then it would be hard as they would not want to block all previously sold AirTags

[crazygringo]

Is there something it can do to whitelist legitimate AirTag serial numbers?

[bhy]

I don't think AirTag work that way. AirTag protocol is specifically designed so Apple or other parties will not be able to track users by serial numbers.

[stonegray]

They do, Airtag hardware need to be signed to add to your iCloud account. But the actual location beacon messages are not linked to your iCloud account and can’t be associated with the sending airtag.