@mcc The feature is currently only for specific providers. And probably more importantly is -completely- different from Chrome's, featuring -far- less information. Unlike Chrome's feature for example, advertisers know nothing about who the likely user of the browser is.
See more technical details here: https://docs.google.com/document/d/1KpdSKD8-Rn0bWPTu4UtK54ks0yv2j22pA5SrAD9av4s
Edit: I incorrectly stated this was not on release yet.
@Schouten_B The above screenshot was taken on my personal computer which I am typing into right now. I am not using Nightly. I am using the Ubuntu Snap distribution, in other words the default web browser for my operating system