Google has begun the process of removing support for third-party cookies from its Chrome browser; by the end of 2021, the browser will no longer allow ad networks to place tracking code on your machine that will be able to track your visits to any site.

This is good news, of course, but one might ask, "Isn't Google's entire business model based on advertising?" or "Doesn't Google own the largest ad network in the world?" Well, you're right.

And that's why the end of third-party cookies does not spell the end of highly personalized Internet-based advertising. [Instead, Google will introduce a new targeted advertising system called FLoC (Federated Learning of Cohorts). This is a browser standard that will be integrated into Chrome in the coming months and is intended to provide a more private way to monitor monetizable interest.

As a way to protect your online privacy, FLoC does not consider you as an individual. Instead, you will be placed in a group (cohort) with others who share similar interests.

This grouping takes place within the browser, allowing the website to simply ask the browser which group you belong to. According to this theory, marketers can create ads tailored to your cohort, but they cannot create ads specific to you.

The cohort to which you ultimately belong (you can only belong to one cohort at a time) is determined by your online behavior. It is determined based on the specific URLs you visit and the actual content of those pages.

For example, if you visit a lot of sites featuring cats, you will be added to that cohort. I am interested in cars. There is a cohort for that. Depending on which sites you visit, you will be assigned a cohort ID in FLoC, which may open up even deeper tracking possibilities as cohort assignments are continually recalculated.

According to Google, the FLoC system is private and no more than a few thousand people are added to a cohort. Cohorts are represented by strings of data, not names, so you will never be in the group of "iPhone owners searching for the best Android phone." If there are enough people looking for it, a cohort will be created and assigned an ID such as FD5642.

The advertising company would then use that information to find out what people in a certain cohort are looking for. The fact that these cohorts are so ambiguous is part of the attraction.

This means that a site cannot simply record your IP address and the cohort that ties you to that data. But they can make assumptions about the cohort, and for the big advertising companies, this gives them some advantage.

You need to worry about any attempts to track you online. However, with the current FLoC system, it is fairly easy to opt out.

One warning. This only applies during the "proof of concept" phase; once FLoC is adopted, the opt-out rules may change.

Google will use your chrome login as the first requirement for your inclusion. You will not be opted out if you have blocked third-party cookies, and you will not be opted out if you have disabled ad personalization in your Google ad settings. For other opt-out methods, please see the GitHub project page.

There is another really important issue. What if I want to search for or read about a sensitive topic?

For example, say you are a victim of domestic violence or are concerned about your health. You could be assigned to a cohort that might reveal that to advertisers.

Certainly possible, but Google will exclude certain topics. There is a list of things that cannot be personalized ads.

The problem is that there is an algorithm that manages this. While all pages containing the keyword may be destroyed, it may not be possible to do this effectively for all.

There is also considerable concern that companies will "fingerprint" your browser using FLoC.

Browser fingerprinting is used to track individual web users when tracking cookies are blocked. This method uses data such as IP address and details that the browser provides to the web server, such as browser type, monitor resolution, operating system, and even devices connected to the computer, such as game controllers and certain audio hardware to Create a browser profile.

Browser fingerprinting is not endorsed by Google, but it is possible to fingerprint any web browser if a website or ad network wishes to use this information. But even the best browser fingerprinting is imperfect. With billions of people online, there are bound to be at least a few people who share your browser profile.

But if you are put into a FLoC with only a few thousand people, the scope of your profiling is much smaller. Combining your browser fingerprint with your FLoC ID, it may actually be very easy to identify you as an individual. Then, ad networks would be able to keep tabs on you as you cruise the web.

The big question would be how easy it would be to undermine the cohort; several questions on the FloC's online discussion page raised the idea of malicious actors using bots to game the cohort, making it large enough to provide high anonymity to its residents The idea of making them appear to be.

But what if the cohort had only one legitimate user and 10,000 bots? That would be a very easy way to identify someone.

Google hopes that the FLoC idea will be adopted by other browser makers. Apple is unlikely to adopt it for Safari. Microsoft and Firefox will have to make their own decisions on whether or not to do so.

It is worth pointing out that of the major web browsers, Safari and Firefox already block third-party cookies by default; Edge and Chrome (the current version) do not; and Firefox and Safari do not block cookies.

Chrome allows you to disable third-party cookies, but Edge is reported to be a bit unreliable in blocking these tracking cookies.