What else could it be but a bitwise AND. If they had used `open_source && privacy_focused && user_controlled`, it would just be `true`, which is hardly an interesting philosophy. This way, you'll be able to do tests like `if (!(philosophy & privacy_focused)) { track_user_activity(); serve_creepy_but_useless_ad_about_something_they_bought_yesterday(); }`. Alternatively, they could have used some kind of set datatype if the number of philosophy variables is large enough, but I think the code would have become unmaintainable if they want to implement every possible philosophical alternative; 64 bits should be enough for everyone.

But, in that case, shouldn't they be using | here?

Silly Mozilla. Everyone knows you use bitwise OR to perform union operations!