> If I want to prefetch results, I unerstand it means people know I'm looking at those results.
Why do that though when you can have your cake and eat it? Google's proposed solution allows you to prefetch results _and_ not allow the third-party to know you're looking at those results.
> the counter consideration is that your implicitly saying you trust Google with that info more than the actual service providers
If I'm using Google search, then yes, obviously I'm fine with Google knowing what I searched for. If I wasn't okay with that, I most certainly would not be using Google search. In contrast, I'm less likely to be okay with a random site in the search results page that I haven't clicked on knowing that I saw a link to their site in a search results page.
Note that if I were using DuckDuckGo instead and DuckDuckGo supported AMP, then my browser would prefetch from DuckDuckGo's AMP cache, not Google's. No additional information is being shared with any party who doesn't already possess that information. (DuckDuckGo already knows what I searched for. Me loading an AMP page from them related to that query reveals no additional information.)
> Indeed. That's the point of HTTPS. As a user I don't expect that contract undermined even by a claimed benevolent Google
Could you explain how Google's proposed solution here undermines HTTPS? Note that the OP talks about using the upcoming [Web Package standard][1] to distribute AMP pages. This standard would allow the integrity guarantees of HTTPS to be preserved even when the page in question is being served by Google's AMP cache rather than the original server.
[1]: https://github.com/WICG/webpackage