My wife is on a business trip. Prior to leaving she forwarded her itinerary to my gmail account. I noticed this morning that Google Maps shows my wife's arrival time for her return flight. I also just noticed that Google Search does the same... I googled "itinerary" to make sure I had spelled it right... and there was her flight info at the top. I expect my search activity to be scanned and used to drive ads, but this is the first time I've seen direct evidence of email scanning.

There is an option to turn it off, but just in case anyone feels their gmail content is really private, it's not.