Consider what to do about locales used by very few people

We give users an option to hide their locale and say they are using en-US as to decrease their fingerprint, but once in a while we can see some information may be leaked (ref: https://trac.torproject.org/projects/tor/query?status=!closed&keywords=~tbb-fingerprinting-locale).

I wonder if we should let users know about this?

Looking at the stats, specially the smaller numbers in Update pings at

I wonder if maybe we should make users aware somehow about this? For example when in the download page:

warning: you are using a locale used by very few people and there are a couple of ways in which your locale may be leaked.

maybe we should also add a note about 'how do we know about this', maybe linking to the metrics page:

it sounds awful for a new translation to be published and get that, though :S