Exactly, this just tells us we need to do a better job about educating people. Many of the conveniences we enjoy come at the expense of personal autonomy and privacy, and in my opinion it's never worth it.

I recently traveled to Canada by road trip, and when I called my bank's number I was surprised to learn that I don't need to report things like this. This actually disturbs me because it shows that they must have some way of collecting sufficient data to show that I am traveling to a specific place at a specific time, and in my opinion my bank has no business knowing this unless I choose to disclose it.

if you travel to another place and use your card there, then your bank are going to know you’re there.

That’s not the same bank that I bought my airfare with. The bank I use to buy the airfare with has no reason to know where I am. IIRC there’s a stat that on avg Americans have like ~15 or so different bank/credit cards. What you’re saying makes no sense. The airline takes the liberty of giving a travel notice to just one of your dozens of banks, and what about the rest?

If there’s a transaction showing you bought tickets to that city/country for the same dates that transactions happen within that city/country, that’s evidence to support one decision over the other on the algorithm’s part.

I often buy a one-way ticket with one card and a one-way return with another. So not even one bank has the full picture. I typically leave those cards at home as well because they have poor forex rates. Yet this doesn’t trip fraud sensors on the cards I carry to the destination. The fraud sensors are tripped when I forget my ATM limit or incorrectly adjust that limit for the foreign currency.

One bank that requires a travel notice doesn’t even accept that a trip would last more than 2 weeks. I call and say I will be gone 3 weeks, or 4 weeks, and they cannot handle it. They say “the travel notice will expire in 2 weeks so you have to call again when that time comes to renew your travel notice”. What I tell them directly carries more weight than whatever shows up on the transactions because they have no way of knowing what other travel arrangements I have. Yet what I tell them is not fully utilized.

The other problem with your theory is travel notices are a recent development of the past ~10—20 years, whereas itineraries have been shared with banks for as long as I can recall (~25+ years). Anyway, speculation isn’t cutting it. Solid info needed on why this is happening.

That’s all plausible. But in the end the airline (their insurance) will be the loser, no?

When a traveler has insurance they have some reassurance & comfort that the loss won’t be theirs as they will file a claim. In my cases of lost luggage, the rules of the traveler’s insurance claim required me to still file a claim with the airline. The airline seemed to have the primary liability. Wouldn’t it be bizarre if the airline (who caused the loss) would get off the hook? My insurance just ensured I was compensated one way or another so long as I followed the rules and reported the loss to the airline. From there, wouldn’t my insurance work in their own interest to ensure the airline pays out? Surely my insurance must only be liable for benefits coverage that exceed the airline’s responsibility (depending on how generous my policy is).

Since an insurance company has the resources and legal muscle to ensure the responsible company pays out, I would expect it to /not/ be in the airline’s interest to deal with another insurance company over a loss. Just about every time I had a loss without insurance, the airline was directly liable to me but they told me to pound sand. Every time IIRC. They wouldn’t get away with that against another insurer.

Most of my cards are free with lousy policies that only pay out if I lose a limb or something like that. It was only when I paid for extra insurance that I got coverage that was useful.

In any case, if you are correct, that implies if I get a payment card with zero insurance (a prepaid card?), then the flight details won’t be shared, correct? Might be interesting to test that, but tricky because prepaid cards often don’t issue a statement.