If this is implemented, there is a risk that a whole host of users are annoyed when they start back up after updating because the default behaviour of the browser is changed.

For what it's worth, I disagree with the request and believe that, if implemented, it should be disabled by default. There are plenty of examples where urls contain querystring params but it would be desirable to restore those tabs (crbug.com being one such example!).

I do believe that there should be the ability to choose what to do on start-up, similar to desktop. Namely:
() Open the New Tab page
() Continue where you left off
() Open a specific page or set of pages (with option to set)

Yeah, I also agree that it should be a setting. Good idea.

Got so put off when I saw that charge on my account statement and it turned out to be a purchased download that was processed twice due to this restoring of tabs. (it restored a "Thank you for your order, here is your downloads" tab with a url like as I shown, with like orderID=xxxxxx in the end causing the order to be performed again). But anyways, it was just 1$ so it don't matter.

But what would happen if that was a 500$ order?

The thing is that if I close the browser manually, I close it because im finished with the session.

I agree that restoring sessions is a good idea, but if that requires sending out requests, it should be more careful IMHO.

Maybe this issue could be solving with some cache system, so even if it restores the session completely, it will always ensure it restores 100% from cache and never sends out network traffic as a result of restoration.