Tags: fingerprinting

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Wednesday, April 21st, 2021

Get the FLoC out

I’ve always liked the way that web browsers are called “user agents” in the world of web standards. It’s such a succinct summation of what browsers are for, or more accurately who browsers are for. Users.

The term makes sense when you consider that the internet is for end users. That’s not to be taken for granted. This assertion is now enshrined in the Internet Engineering Task Force’s RFC 8890—like Magna Carta for the network age. It’s also a great example of prioritisation in a design principle:

When there is a conflict between the interests of end users of the Internet and other parties, IETF decisions should favor end users.

So when a web browser—ostensibly an agent for the user—prioritises user-hostile third parties, we get upset.

Google Chrome—ostensibly an agent for the user—is running an origin trial for Federated Learning of Cohorts (FLoC). This is not a technology that serves the end user. It is a technology that serves third parties who want to target end users. The most common use case is behavioural advertising, but targetting could be applied for more nefarious purposes.

The Electronic Frontier Foundation wrote an explainer last month: Google Is Testing Its Controversial New Ad Targeting Tech in Millions of Browsers. Here’s What We Know.

Let’s back up a minute and look at why this is happening. End users are routinely targeted today (for behavioural advertising and other use cases) through third-party cookies. Some user agents like Apple’s Safari and Mozilla’s Firefox are stamping down on this, disabling third party cookies by default.

Seeing which way the wind is blowing, Google’s Chrome browser will also disable third-party cookies at some time in the future (they’re waiting to shut that barn door until the fire is good’n’raging). But Google isn’t just in the browser business. Google is also in the ad tech business. So they still want to advertisers to be able to target end users.

Yes, this is quite the cognitive dissonance: one part of the business is building a user agent while a different part of the company is working on ways of tracking end users. It’s almost as if one company shouldn’t simultaneously be the market leader in three separate industries: search, advertising, and web browsing. (Seriously though, I honestly think Google’s search engine would get better if it were split off from the parent company, and I think that Google’s web browser would also get better if it were a separate enterprise.)

Anyway, one possible way of tracking users without technically tracking individual users is to assign them to buckets, or cohorts of interest based on their browsing habits. Does that make you feel safer? Me neither.

That’s what Google is testing with the origin trial of FLoC.

If you, as an end user, don’t wish to be experimented on like this, there are a few things you can do:

  • Don’t use Chrome. No other web browser is participating in this experiment. I recommend Firefox.
  • If you want to continue to use Chrome, install the Duck Duck Go Chrome extension.
  • Alternatively, if you manually disable third-party cookies, your Chrome browser won’t be included in the experiment.
  • Or you could move to Europe. The origin trial won’t be enabled for users in the European Union, which is coincidentally where GDPR applies.

That last decision is interesting. On the one hand, the origin trial is supposed to be on a small scale, hence the lack of European countries. On the other hand, the origin trial is “opt out” instead of “opt in” so that they can gather a big enough data set. Weird.

The plan is that if and when FLoC launches, websites would have to opt in to it. And when I say “plan”, I meanbest guess.”

I, for one, am filled with confidence that Google would never pull a bait-and-switch with their technologies.

In the meantime, if you’re a website owner, you have to opt your website out of the origin trial. You can do this by sending a server header. A meta element won’t do the trick, I’m afraid.

I’ve done it for my sites, which are served using Apache. I’ve got this in my .conf file:

<IfModule mod_headers.c>
Header always set Permissions-Policy "interest-cohort=()"
</IfModule>

If you don’t have access to your server, tough luck. But if your site runs on Wordpress, there’s a proposal to opt out of FLoC by default.

Interestingly, none of the Chrome devs that I follow are saying anything about FLoC. They’re usually quite chatty about proposals for potential standards, but I suspect that this one might be embarrassing for them. It was a similar situation with AMP. In that case, Google abused its monopoly position in search to blackmail publishers into using Google’s format. Now Google’s monopoly in advertising is compromising the integrity of its browser. In both cases, it makes it hard for Chrome devs claiming to have the web’s best interests at heart.

But one of the advantages of having a huge share of the browser market is that Chrome can just plough ahead and unilaterily implement whatever it wants even if there’s no consensus from other browser makers. So that’s what Google is doing with FLoC. But their justification for doing this doesn’t really work unless other browsers play along.

Here’s Google’s logic:

  1. Third-party cookies are on their way out so advertisers will no longer be able to use that technology to target users.
  2. If we don’t provide an alternative, advertisers and other third parties will use fingerprinting, which we all agree is very bad.
  3. So let’s implement Federated Learning of Cohorts so that advertisers won’t use fingerprinting.

The problem is with step three. The theory is that if FLoC gives third parties what they need, then they won’t reach for fingerprinting. Even if there were any validity to that hypothesis, the only chance it has of working is if every browser joins in with FLoC. Otherwise ad tech companies are leaving money on the table. Can you seriously imagine third parties deciding that they just won’t target iPhone or iPad users any more? Remember that Safari is the only real browser on iOS so unless FLoC is implemented by Apple, third parties can’t reach those people …unless those third parties use fingerprinting instead.

Google have set up a situation where it looks like FLoC is going head-to-head with fingerprinting. But if FLoC becomes a reality, it won’t be instead of fingerprinting, it will be in addition to fingerprinting.

Google is quite right to point out that fingerprinting is A Very Bad Thing. But their concerns about fingerprinting sound very hollow when you see that Chrome is pushing ahead and implementing a raft of browser APIs that other browser makers quite rightly point out enable more fingerprinting: Battery Status, Proximity Sensor, Ambient Light Sensor and so on.

When it comes to those APIs, the message from Google is that fingerprinting is a solveable problem.

But when it comes to third party tracking, the message from Google is that fingerprinting is inevitable and so we must provide an alternative.

Which one is it?

Google’s flimsy logic for why FLoC is supposedly good for end users just doesn’t hold up. If they were honest and said that it’s to maintain the status quo of the ad tech industry, it would make much more sense.

The flaw in Google’s reasoning is the fundamental idea that tracking is necessary for advertising. That’s simply not true. Sacrificing user privacy is fundamental to behavioural advertising …but behavioural advertising is not the only kind of advertising. It isn’t even a very good kind of advertising.

Marko Saric sums it up:

FLoC seems to be Google’s way of saving a dying business. They are trying to keep targeted ads going by making them more “privacy-friendly” and “anonymous”. But behavioral profiling and targeted advertisement is not compatible with a privacy-respecting web.

What’s striking is that the very monopolies that make Google and Facebook the leaders in behavioural advertising would also make them the leaders in contextual advertising. Almost everyone uses Google’s search engine. Almost everyone uses Facebook’s social network. An advertising model based on what you’re currently looking at would keep Google and Facebook in their dominant positions.

Google made their first many billions exclusively on contextual advertising. Google now prefers to push the message that behavioral advertising based on personal data collection is superior but there is simply no trustworthy evidence to that.

I sincerely hope that Chrome will align with Safari, Firefox, Vivaldi, Brave, Edge and every other web browser. Everyone already agrees that fingerprinting is the real enemy. Imagine the combined brainpower that could be brought to bear on that problem if all browsers made user privacy a priority.

Until that day, I’m not sure that Google Chrome can be considered a user agent.

Friday, February 12th, 2021

supercookie • workwise

Favicons are snitches.

Thursday, April 11th, 2019

Accessibility Events | CSS-Tricks

If you’re using Apple’s VoiceOver, both your phone and your computer will broadcast your assumed disability to the entire internet, unless and until you specifically tell it to stop.

Thursday, April 4th, 2019

Apple’s new feature a step towards digital apartheid - Axess Lab

I also discussed this accessibility events feature with my friend who is a screen reader user herself. She said it feels like it’s a first step towards a well-meant digital apartheid.

Monday, October 22nd, 2018

So We Got Tracked Anyway

Even using a strict cookie policy won’t help when Facebook and Google are using TLS to fingerprint users. Time to get more paranoid:

HTTPS session identifiers can be disabled in Mozilla products manually by setting ‘security.ssl.disablesessionidentifiers’ in about:config.