This is something all sites do if your logged into your accounts and detects a active login will ask for this. My advice don't let it use your account login as they will track all your activity when you do this. Login in with the eBay login itself not with your google account login.

Is there any way to turn this off. Its really annoying. I would never even use it. Like you said, privacy!

[Profanity removed by moderator. Please read Mozilla Support rules and guidelines, thanks.]

Hi annoyedagain, Some sites see using your Google account as a convenience to you, so you won't have to create a new account/password. They pass on authentication to Google, who then says "Hey, this person is already signed in to Google, so we'll just use the account they're already signed in to."

If you want to disable sites from using that feature, you might like the Google Container add-on at https://addons.mozilla.org/en-US/firefox/addon/google-container/

For instructions on how to install add-ons, see Find and install add-ons to add features to Firefox

I tried the google container add-on. Didnt work for me.

Is your eBay sign-in screen different when you are signed out of Google vs. when you are signed in? I tested in a private window and they looked the same to me (before and after screenshots attached).

My sign in page screens look the same. The issue shows up on the www.ebay.com page, which is my linked landing page from a shortcut I have. It seems to happen the first time I link. Ive tried other approaches, so but far have not replicated the issue. So specifically, what I am doing is. 1) launch browser 2) sign in to google (typically, thats google voice for me) 3) open a new tab 4) go to www.ebay.com

and then after a few seconds..the annoying message.

(this happens even with the google container add-on enabled (or not)

Thank you for the steps. I see that now. eBay is creating a frame that calls a script from https://smartlock.google.com/client and then triggering that script to set up the login box if you are logged in.

If you never want to log in with Google, you might be able to block that server, but I can't be sure it isn't used for anything useful. If you use uBlock Origin or AdBlock Plus, you can use a filter. This thread has the steps (I haven't tested myself):

https://superuser.com/questions/1414410/how-to-disable-pop-ups-for-google-yolo-one-tap-sign-up-in-chrome

Edit: Added a screenshot showing where the frames are inserted.