Unlike other reply, I do not work at Brave, and I can also confirm that Brave never did that. They do have their own ads but those have always been opt in (you are not opted in by default), and they do pay some small amount of USD in their crypto token for opting in to those - it's pennies. People scoff at the pennies but guess who pays out nothing to show you ads against your will - literally everyone else.
What you may be thinking of was at one point, when you went to a URL (for some URLs), the browser would rewrite the URL to contain their affiliate link. There was blowback for doing that. They quickly removed that/haven't done it since as far as I know
The grants came from our token fund, not users' tokens (no way to buy BAT then).
The issue which I found out about late, and fixed right away, was infringing on right to publicity, nothing to do with donations from users' own tokens.
Already shared, but that (what you linked to) was a proposal and no deliverable was ever publicly released. A simple prototype was made and tested by a limited number of employees - instead of showing an ad, it would show a picture of a mustachioed man as a placeholder. That silly picture would be replaced with real code if the idea panned out. It didn't. The idea and the code was canned before I joined Brave and I've been here for almost 10 years (I joined August 2016).
Disclaimer in case it's not obvious: I am a Brave employee
I definitely tried out brave several years ago and legit got lots of crypto ads. I really don’t know how you are getting upvoted for lying about this.
Maybe what GP remember is the VPN they secretly installed, the affiliate links they silently added, the donations they took for other companies and kept for themselves, or one of the other times Brave was caught. It is a wonder people think the code base is trustworthy when we know for a fact how they behave with stuff we can see. But sure, try to make it look like it has anything to do with a person hardly anyone have ever heard of.
With the number of times the above lie has been repeated and corrected, virtually every single Brave thread for several years straight now, I am inclined to think it's actually maliciousness which is motivating people to continue posting it.
What you may be thinking of was at one point, when you went to a URL (for some URLs), the browser would rewrite the URL to contain their affiliate link. There was blowback for doing that. They quickly removed that/haven't done it since as far as I know