[tgb]

I misunerstood the part I quoted, I thought it was about web pages asking you to log in via Google/Facebook. So the problem I was thinking of is more generally entering Google credentials into logins provided to us by a third party. The "don't use the link in your email to log into google, go to gmail.com instead" advice has been seriously degraded by this. It should always be that if you aren't already logged in, you have to go yourself to gmail/facebook/etc and log in there.