There was no tracking on Cliqz, nor it will be any in Brave. To know more about the underlying tech of Cliqz there are interesting posts at https://0x65.dev, some of them covering how signals are collected, data, but no tracking. I did work at Cliqz and now I work at Brave. I can tell for a fact, that all data was, is and will be, record-unlinkable. That means that no-one, not me, not the government, not the ad department can reconstruct a session with your activity. Again, there is no tracking, full anonymity, Brave would not do it any other way.