The jury is still out on how this will work. We dont have tons of information from Apple.
For instance, Apple keeps marketing these as “find items” tool and not an anti-theft tool. The difference is very important. Apple has put a huge amount of thought into the Privacy side of things and therefore some features will prevent or work against the anti-theft portion.
One feature that is concerning to me is the fact that your iPhone will identify if there is an airtag (that is not yours) that is traveling with you. At this point, you can disable the airtag. This is mainly to prevent stalkers and somebody tagging you, but at the same time, it also means that if you grab a bike and ride around for a bit, your iPhone will tell you there is an airtag on the bike and you can disable it. The timing of this is not super clear, but the apple website shows an example:
Using their own example, we could assume a bike was stolen at the airport at 8:50am and you rode it around an at 9:41am, your iPhone tells you there is an airtag following you. You can then make it play a sound or disable it. I think this assumes that the owner has not reported it lost. What is not clear is the timing the owner has to report it lost before it notifies the thief that it is tagged.
I have also heard that the tag will play a sound if it is moving without the owner. Not sure if this can be disabled or not. I would hate to lend my bike to somebody (not that I actually do) and then have the beeping start…
Like I said… I need a bit more information from Apple or reviewer on how the actual system works.