Unfortunately, the plugins.enumerable_names feature was disabled and later removed (by me, sorry). [1] There was no way Firefox would be able to ship that feature because it broke too many websites for the minor reduction in fingerprinting. Even with your plugins "hidden", websites could still use Flash to enumerate all your system fonts.

The navigator.plugins array is now sorted alphabetically [2] to avoid an issue documented in Jonathan Mayer's thesis [3]. Gecko and WebKit sorted the navigator.plugins array by the plugins' "last modified" time. Users with the same plugins installed can still have unique fingerprints because it is unlikely that they installed their plugins in the same order.

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=1169945

[2] https://bugzilla.mozilla.org/show_bug.cgi?id=793978

[3] https://www.stanford.edu/~jmayer/papers/thesis09.pdf

My answer is based exclusively in what you wrote, and not in my technical knowledge of Firefox's internals.

- There is no such thing as "minor" reduction in fingerprinting nowadays. This is a war, every little bit is important.

- I much prefer to have a thousand sites broken and a little bit more of privacy (or the feeling I'm doing all I can).

- A lot of people (me included) do not use Flash anyway.

Thank you for your work!

This is a very good point and I agree. How is this different from saying "we didn't fix the flaw because people exploit it"?

Thank you for your hard work on Firefox, Chris. Mozilla has made many good decisions with it, keeping it clearly superior to Chrome/IE in my view.

That said, I find it difficult to agree with the decision to remove features like this. So what if it can break websites? Isn't that what the "This might void your warranty!" warning is for? It seems far better to give users the option of viewing the web the way they want to view it, rather than protecting them from some broken websites at the expense of their privacy.

Or use the opportunity to kick flash off your system. I'm surfing without flash for probably 2 to 3 years now. These days it's really not a problem. Most sites work with html5 and those that don't have alernatives that do.