At least here in Germany it is opt in. As the algorithm runs locally, I don't see a big issue with this.
I didn't opt in to this feature to be clear, and ghostery should help for tracking.
But if I wouldn't have this option, I would be more willing to have my history evaluated locally, instead of having my history evaluated for 90% of the sides on some third party advertisers owned system.
Hm. I was going to write "because I could have been visiting sites that don't sell my data to Google or other advertisers. And now those fuckers will have this information." But then, if I use Google Chrome to visit those sites, then it serves me right.
People keep telling me that, but everytime I tried Chrome my computer would lag and the fan felt like it was getting ready to take off. On multiple conputers
When it first took big bites out of Firefox, it wasn't slight at all. I have only my hazy human memory on this, but some pals and I ran a test script at the time. Iirc, Chome would routinely load enough to start reading in 2 seconds while Firefox was more like 6 on average with our site list and went over 10 way too often to ignore.
It had been very easy before that to blame the sites for all the crud they were larding in. But it was like Google's clean, fast search page compared to Yahoo's "junk you don't need" frontpage all over again. Chrome won on speed fair and square.
While the Mozilla foundation had designed browser DRM that worked on Linux, Chrome has the first implementation. And that enabled Linux users to watch Netflix.
Next one: forced fucking cloudflare DNS over HTTPS. I dipped Firefox because of that.
Sure, Firefox introduced a security feature: DNS over HTTPs. So instead if asking some DNS server that is configured on the local system, for the IP that belongs to a Domain name, am external service is asked via HTTPs.
While this is in theory a good idea, and has some benefits, the Firefox implementation was bad:
the external partner was cloudflare. There where no additional informations out at that time.
there where no opt out option
Users, that where forced into DNS over HTTPS could no longer resolve internal hostnames. This was a killer in office environments. And after the fix for that, everything was first submitted to cloudflare and only if cloudflare could not resolve the hostname, the local DNS server was asked, leading to potential information leaks. Also a no go for companies.
Firefox has fixed these issues by providing privacy policies, the option to choose other DNS over HTTPS providers and the option to define what domains should never be resolved externally.
But they lost trust in many professional environments because of that move.
I totally forgot one essential fact: the reason for DNS over HTTPS itself was perfectly valid: ISP's in the US are using DNS lookups of their customers for advertising. The idea is to prevent this kind of privacy breach. And it is very effective against it.
I guess that most advertisers cannot track you everywhere, while your history has the full information.
Anyway, happy Firefox user here, I am just shocked how the Google monopoly on browsers is playing out, especially since I am forced to use Chrome for some websites.