It would be cool if there were a special browser badge for a website that ensured uploaded content couldn't be transmitted to the server.
Something in the spirit of `Content-Security-Policy: connect-src 'none';` (not sure if that covers all edge cases though, I'm not super familiar with CSP)
Maybe it could add the CSP at some point after everything is loaded and then the badge appears? Of course you still want updates, how do you ensure that updates can occur without sneaking out information? Wiping all site data before downloading the new version would work but having local persistent data would be useful. Maybe all local data would be unavailable from the start of the new version fetch to until the no-network policy is applied?
But when you think about it, we're asking a tool originally designed to browse documents on the web, to now execute what is essentially a (safe) binary application, and not to let it connect to the internet, while inside a document in a web browser.
I can't see how the future of the desktop is not going to be radically shaped by WASM, in whatever form that takes.
maybe an html meta tag that blocks all XMLHTTPRequests until the user consents. i don't think it would even matter if it was browser-specific
Of course that being said the policy would basically have to be "disable network" at a trigger point not just uploads as you can just as easily leak large amounts of data via triggering GETs by making img placeholders come into view or other equally tricky things that can't be distinguished from "app is just still loading".
For example...
1. Cross origin hyperlinks would have to be completely disabled 2. Same-origin URLs would need all url information (query params, path, etc) to remain completely client-side. The only thing transmitted to the server would be the base domain.
It's interesting to think about, at least.
Surely, though, a blocked network request never reaches the server and so it can't be used a 'flag'?