[mcstempel]

CAPTCHAs have been ineffective as a true "bot detection" technique for a while as tools like anti-captcha.com allow for outsourcing it to real humans. BUT they have been successful at the economic side of raising the cost of programmatic traffic on your site (which is good enough for some use cases)

As the author of this agent detection post, we agree that CAPTCHA and vanilla browser/device fingerprinting is quickly not going to be very valuable in isolation, but we still see a lot of value in advanced network/device/browser fingerprinting

The main reason is that the underlying corpus & specificity of browser/device/network data points you get from fingerprinting makes it much easier to build more robust systems on top of it than a binary CAPTCHA challenge. For us, we've found it very useful to still have all of the foundational fingerprinting data as a primitive because it let us build a comprehensive historical database of genuine browser signatures to train our ML models to detect subtle emulations, which can reliably distinguish between authentic browsers and agent-driven imitations

That works really well for the OpenAI/BrowserBase models. Where that gets tricky is the computer-use agents where it's actually putting its hands on your keyboard and driving your real browser. Still though, it's valuable to have the underlying fingerprinting data points because you can still create intelligent rate limits on particular device characteristics and increase the cost of an attack by forcing the actor to buy additional hardware to run it

[ATechGuy]

I don't think tracking everything is the way to go; info would get outdated very soon and tracking compromises user privacy. A simple solution could be to throw a challenge that humans can easily solve, but agents absolutely cannot now or in the future (think non-audio/visual/text).