Google's plan to replace third-party cookies is, on one level, really quite brilliant. Google's entire business depends heavily on the ability to track users in order to identify their interests and then show them "personalized ads" based on their Web activity. The third-party cookie is a huge part of that business, which means it makes sense Google would want to be leading the way on whatever replaces it.

Cookies, if you remember, are little snippets of code that websites use to identify you when you navigate across the internet. Not all of them are bad. For example, first-party cookies are used to keep you logged in to websites. That's helpful, and most people find it convenient that the CRM they use every day remembers them so they don't have to enter their login information every time they open their browser.

Third-party cookies, however, are mostly used by advertisers and ad platforms -- like Google and Facebook -- to track pretty much everything you do online. That's bad. 

It's also very profitable, which is why Google created FLoC and is pushing it as the alternative for advertisers moving forward. Of course, setting aside the privacy implications (which I'll get to in a minute), no one actually knows if it will work. 

This is precisely why Google recently started testing FLoC at the end of last month. Except, there's a problem -- two really.

The first is that Google's test has been rolled out to users without their consent. If you're using Chrome, you could be one of them. 

This is how Google explained it in a statement announcing it was rolling out the test at the end of last month:

The initial testing of FLoC is taking place with a small percentage of users in Australia, Brazil, Canada, India, Indonesia, Japan, Mexico, New Zealand, Philippines, and the U.S. We'll expand to other regions as the trial expands globally. If you've chosen to block third-party cookies with the current version of Chrome, you won't be included in these origin trials. In April, we'll introduce a control in Chrome Settings that you can use to opt-out of inclusion in FLoC and other Privacy Sandbox proposals.

Google will tell you that the test affects only 0.5 percent of Chrome users. That's true, except there are 2.65 billion Chrome users, which means that even half a percent of those is still 132 million people. 

That's a lot of people who got signed up for a new form of Web tracking without their knowledge or consent. And, despite the fact that FLoC is supposed to be more anonymous, it really isn't. 

It uses your browsing history from the past week to assign you to a group with other "similar" people around the world. Each group receives a label, called a FLoC ID, which is supposed to capture meaningful information about your habits and interests. FLoC then displays this label to everyone you interact with on the web. This makes it easier to identify you with browser fingerprinting, and it gives trackers a head start on profiling you.

By the way, if you use Chrome and want to know if you are a part of the test, the EFF site linked above will tell you.

The second problem is that no other browser has committed to using FLoC. I guess that's only a problem for Google. It's probably a good thing for the rest of us. 

Not only that, but companies that make alternatives to Chrome have started to indicate they have no intention to participate in FLoC at all. For example, Brave said it "opposes FLoC, along with any other feature designed to share information about you and your interests without your fully informed consent." Brave also says that it will disable FLoC completely in its browser.

And, in a tweet, an Apple WebKit engineer said that Safari has no plans to use FLoC either. 

Maybe most importantly, Microsoft told The Verge in a statement: "we do not support solutions that leverage non-consented user identity signals, such as fingerprinting." That's significant because Edge is the second-most-popular Chromium browser (Chromium is the open-source project behind Chrome). 

The fact that no other browsers have committed to FLoC may not matter to Google, considering that Chrome is by far the most popular desktop browser. The company may be happy enough to go it alone in order to support its ad platform. On the other hand, as users become more aware of how companies use their data, it seems likely that many of them will be happy to choose a browser that isn't tracking everything they do online.