[T-hawk]

Problem with that is the surprisingly large number of legitimate sites that break without third-party cookies. Things like when verizon.com has an element from verizononline.com, which sets a login cookie that verizononline.com expects to read. "Shun brokenly-coded sites" is not an option for something as vital as paying my phone bill.

I'd love an option to accept third-party cookies but delete them on browser exit, while retaining legitimate first-party cookies as usual. Does any of the major browsers have that?

[ck2]

An alternative to third party cookies for login sites is to do a fast forward redirect through the main site for the login and then back again to the destination.

If done properly the user will barely notice or care and it's certainly less invasive than forcing 3rd party cookies to be used.