It's an interesting question. Maybe it's just scare tactics. The battery that goes in an AirTag is the same as in a lot of wristwatches and I expect it would look like a wristwatch via x-ray. And it is exactly as dangerous as such a thing, which it to say: not.

>The battery that goes in an AirTag is the same as in a lot of wristwatches and I expect it would look like a wristwatch via x-ray.

If it's just scare tactics then the similarity to watches is irrelevant. However, if for whatever reason they want to crack down on it, it being similar to wristwatches isn't going to stop them. I suspect most wristwatches are kept with the person rather than in checked luggage, and that if were actually determined they could demand a search of your luggage if they spot anything that remotely looks like an airtag on x-ray.

Does security handle airline specific requirements? I’ve flown a lot and don’t think I’ve ever experienced that, but maybe?

Well, if they are transmitting, at least in theory it would be possible to detect that transmission. Though I would be kind of surprised if they actually put much effort into actually enforcing it.

But then why is inflight wifi a thing?

Under FAA rules (what I’m familiar with, EU/DE/ICAO is probably similar), the air carrier can determine which portable electronic devices to allow.

The law (it’s short): https://www.law.cornell.edu/cfr/text/14/91.21

An advisory circular relating to it: https://www.faa.gov/documentLibrary/media/Advisory_Circular/...

This allows an air carrier to approve anything they’re confident won’t cause an issue but not approve AirTags.

If they want to defeat tracking, they can enforce their baggage employees not to bring iPhones to work. Of course eventually on the plane, the luggage will be like ten feet below hundreds of people who might have an iPhone!