Cookies can be hijacked by “packet-sniffers” on the Internet, in the same way that any data we send or receive can be detected, even emails. This is dangerous is websites store sensitive personal data in their cookies such as passwords, or banking info.

Third-party cookies are not malicious, however, and most modern browsers allow you to turn them off if you want. When we visit a site such as blogs, there may be some google ads or some other “third-party content”. This content is served by a different server (such as an ads server) which has the right to store its own cookie for its own use. However, they cannot see the cookies of the hosting (or primary) server.

So, if the google ads server stores a cookie on our browser when we visit a site, anonymously identifying us as “a specific user”, it can make the connection to us when we visit another site with google ads. So, if we are visiting a number of wedding-related sites, or even click-thru some of the google ads on weddings, it is able to conclude that we are interested in weddings and will gear the ad content to our preferences, hoping for more ad clicks.

My understanding, however, is that these google ad cookies are used only for “sponsored links” and not for organic search results. While google search results are heavily influenced by geo-location (frustratingly so, suppose I am planning to travel away from my home town, G?), they are not so fluid as that. Also, G recognizes which searches are “global” versus “local”, as well as favouring web servers hosted in our respective countries.

Remember that google search and google ads are two separate arms of G using separate techniques and algorithms. They don’t really “talk” to each other.

Is this a partnership thing?

Is this a privacy violation? I wonder how many privacy policies that contravenes?

It’s not uncommon for a website’s privacy policy to mention why cookies are being set and how they will be used, but I’ve never seen a policy stating that “Google will hijack our cookies and use them for their own purposes.”

I thought cookies are supposed to be encrypted, Is Google hacking them or have they been given the code to open them up.

Or are they just setting/reading their own cookies based on users’ previous search behaviour?

One little blog post, so many questions.