https://support.mozilla.org/en-US/kb/lookingglass The Mr. Robot series centers around the theme of online privacy and security. One of the 10 guiding principles of Mozilla's mission is that individuals' security and privacy on the internet are fundamental and must not be treated as optional. The more people know about what information they are sharing online, the more they can protect their privacy. ...which you've d…
If you clicked on the link about shield studies you'd see it says they're opt in, did you not getting prompted about it?
Anyways, I've taken the opportunity to opt-out of Firefox.