> There's a difference between Signed out, and Incognito (no cookies)!
Is there? I was under the impression that Incognito and its cousins generally still accept and preserve cookies for the duration of the temporary session. This means that for this purpose, there isn't really a difference.
Incognito is supposed to give you a completely clean session that doesn't carry over the cache, cookies, etc. from your normal browsing context.
In this study, my understanding is that result personalization carried over from a normal browsing session into the clean, Incognito session, likely due to IP correlation or possibly through User-Agent strings. So while Incognito has its own context that is wiped once the session has ended, the result personalization didn't need anything saved in the browser to recognize who you are.
Hmmm I wonder if using a second browser, maybe based on a different renderer, in incognito with a different user-agent set up would be enough or if it would still get enough info. At that point it would still have your outgoing ip address at least is there anything else they could still match to a signed in session? I guess you could also route all traffic in the unsigned in session through a VPN too.
Incognito will accept new cookies but to my understanding it won't serve existing cookies that pre-date the Incognito session. A fresh Incognito window is supposed to be like you cleared your history and cookies before opening it, and then cleared them again when you close it. But yeah, in between the browser acts as normal.
In a normal (not Incognito) browser window, you don't have to be logged into Google for Google to read Google cookies. Logging out doesn't make you anonymous; they still know who you are.
Is there? I was under the impression that Incognito and its cousins generally still accept and preserve cookies for the duration of the temporary session. This means that for this purpose, there isn't really a difference.