The idea that there’s a nefarious plot to do something super evil with this data is a bit crackpot though based on their incentives.

Remember, Google = Ads. Their only focus and only care. Their mission statement, rendered accurately, is “Ads ads ads ads. Effective ads. Ads worth paying a lot for. Ads ads ads. Advertising and ads.”

If they choose to be evil in some additional way, (1) remember, they would only do that if in some way it serves their advertising needs — not to offer innovative new black-hat databroker services to airlines, and (2) this little dataset will not need to be re-identified. They’ll just use the 20 years of email and search data they already have on like half the world’s population.