activity-stream VS adblock-rust

Stock Firefox has trackers built into every last part of it. For example, have you ever click on one of the shortcuts on the default new tab? The details of that click is sent off to Mozilla's servers.

Also, even things as simple as interacting with your new tab is collected and sent to Mozilla's servers.

Being FOSS doesn't make it trust worthy. For example, the firefox home tab is entirely open source, but it will report tons of metrics, which are all opt-out, not opt-in.

You also say that FF uses this data for "features that do not serve the user in any meaningful way." I argue this isn't true - all data sent back is used for your security to update your blocklists, for your convenience to pre-load websites, or for Mozilla to know how to continue developing the browser (which is the most straight-forward to disable). They (say that they) don't use any of the data for monetary gain: ** Mozilla never shares data with any third party.** (this is also the source you linked in the OP).

Performing a search, Clicking a top site item, Deleting an item from history, Blocking a site Bookmarking a link, Removing a bookmark from a link, Opening a link in a new window, Opening a link in a new private window, Opening the new tab preferences pane, Closing the new tab preferences pane, Acknowledging a section disclaimer, Adding or editing a new TopSite, Requesting a custom screenshot preview, Session end, Impression stats, Click/block/save_to_pocket ping, Addon initialization failure, Domain affinity calculation.

Brave has written their own (open source) adblock engine (in rust) that is directly integrated into the browser (ie. not an extension, so is not affected by Manifest V3).

https://github.com/brave/adblock-rust

Here is a (somewhat dated) article describing it by the authors:

https://brave.com/improved-ad-blocker-performance/

Brave has its own Rust implementation of an adblocker embedded in the browser: https://github.com/brave/adblock-rust; so it does not embed uBlock Origin (but the filters are mostly compatible)

Disclaimer: I work at Brave but not on the browser.

We support :has currently, which impacts many filters in EL and uBO. Some non-supported filters such as upward() can be manually converted over to use :has instead. The other unsupported procedual filters are a WIP will depend how easy/hard they are implement. No ETA, but have opened a ticket https://github.com/brave/adblock-rust/issues/293

ublock on chromium and brave itself can't use all of the filters in that list: https://github.com/brave/adblock-rust/issues/4

It's open source https://github.com/brave/adblock-rust

I've fixed this in the adblock engine as of https://github.com/brave/adblock-rust/commit/8a755bdb190bb55a3a3acee1e6507085051bdeec, and I'll push to get this patched in 1.47 soon. Thanks for the reports!