There's a Firefox extension called Priv8 [1] which is meant to do that. However, given that FF doesn't have sandboxes and SOP is (AFAIK) the main isolation sys

There's a Firefox extension called Priv8 [1] which is meant to do that. However, given that FF doesn't have sandboxes and SOP is (AFAIK) the main isolation system, I wonder whether it's possible for one origin to somehow sniff the presence of different sessions in the same client via, say, some JS info leak. [1] http://143th.net/post/105342885096/priv8-is-out http://143th.net/post/105342885096/priv8-is-out