Obviously you'd need to know how they're measuring the effect. And I think that's the problem: Firefox doesn't make that easy enough. If Firefox gave on install

Obviously you'd need to know how they're measuring the effect. And I think that's the problem: Firefox doesn't make that easy enough. If Firefox gave on installation * a short list of all the data they could collect, and * a promise that they won't collect anything else without asking for the user's consent again, then I doubt anyone would complain.