Uh, this is not a secret. Google says specifically that web history is a way to personalize your search results, nothing more. Web history is an add-on to Google's normal tracking.
"You can delete information from Web History using the remove feature, and it will be removed from the service. However, as is common practice in the industry, and as outlined in the Google Privacy Policy, Google maintains a separate logs system for auditing purposes and to help us improve the quality of our services for users."
This refers you to the main privacy policy, which says very clearly that Google stores every request you make along with cookies that uniquely identify your account.
Web History is an add-on tracking system. Google does not permit opting-out of Google's regular tracking system, which at one point stored every request you had ever made to any Google server, but which I think now may be semi-anonymized after a couple of years, if I remember their changing policies correctly. Although, the Privacy Policy makes no such promise, so perhaps they do still keep every request ever made in Google's existence. Google absolutely has a perfect record of every interaction you've had with them for the past year or two. Even if Web History is "off".
I'm sorry but I distinctly got the impression that 'opting out' of the search history feature meant that google would not be saving my search history and I'm quite surprised that this is not the case.
It is of course possible that I'm alone in this but somehow I doubt that.
I'm surprised that you would come to that conclusion. I would think that most "mega power-users" (as I'm now labeling you :) would simply assume that they were turning off some kind of public-facing display of their search history, and that you were not opting out of their ability to target ads at you with greater precision.
I would not be surprised if many people got the same impression.
I think what blindsided me was a combination of two factors: (1) I want to believe that google tries to be the 'good guy', (2) the specific wording of the history feature which states that "Get results and recommendations that are tailored to your preferences.", as in "before you enable this feature we can not do that". That feels like an opt-in.
The fact that it is only available to logged in users and that - as far as I can see - it is not public facing, but just to you specifically further increased that expectation.
Yeah, I can see now why it would give off that impression. That feature is going to give them so many issues in the future. I wouldn't be surprised to hear about its removal one day.
Could the difference be that Google associates data with your Google account if you have Web History turned on, but only uses IP addresses in their "logs system"?
If this was the case, IMHO, it would be consistent enough with expectations.
Based on Google's "What Google knows about you" page[1] I would have to conclude that their logs associate your search behavior with your account either way.
That's the doubleclick cookie personalization, which they aren't allowed to tie to your account based on the doubleclick acquisition agreement (which is why "on the web" and "on search and gmail" are separate and why if you go in an incognito window or block doubleclick cookies it will say it has nothing on you).
I don't believe this is quite correct. The EFF article clarifies this in an update:
> [UPDATE 2/22/2012]: Note that disabling Web History in your Google account will not prevent Google from gathering and storing this information and using it for internal purposes. It also does not change the fact that any information gathered and stored by Google could be sought by law enforcement.
> With Web History enabled, Google will keep these records indefinitely; with it disabled, they will be partially anonymized after 18 months, and certain kinds of uses, including sending you customized search results, will be prevented. If you want to do more to reduce the records Google keeps, the advice in EFF's Six Tips to Protect Your Search Privacy white paper remains relevant.
I found this link in google's privacy FAQ, but there may be a better one out there:
Of course, they unhelpfully don't enumerate all the uses of that log data, but it seems pretty clear that it isn't for personalization and (as far as I can tell) it isn't even changed at all by the new privacy policy anyway.
edit: it also appears that they log by a cookie ID that isn't tied to the account. You could probably still reconstruct account information for many users (and even after anonymization a lot is revealable (see the AOL search logs debacle)), but, again, this is quite different than logging data associated with an account and using it to target advertising.
> We strike a reasonable balance between the competing pressures we face, such as the privacy of our users, the security of our systems and the need for innovation. We believe anonymizing IP addresses after 9 months and cookies in our search engine logs after 18 months strikes the right balance.
"You can delete information from Web History using the remove feature, and it will be removed from the service. However, as is common practice in the industry, and as outlined in the Google Privacy Policy, Google maintains a separate logs system for auditing purposes and to help us improve the quality of our services for users."
This refers you to the main privacy policy, which says very clearly that Google stores every request you make along with cookies that uniquely identify your account.
http://www.google.com/policies/privacy/
Web History is an add-on tracking system. Google does not permit opting-out of Google's regular tracking system, which at one point stored every request you had ever made to any Google server, but which I think now may be semi-anonymized after a couple of years, if I remember their changing policies correctly. Although, the Privacy Policy makes no such promise, so perhaps they do still keep every request ever made in Google's existence. Google absolutely has a perfect record of every interaction you've had with them for the past year or two. Even if Web History is "off".