IIRC, GNU Units was once the center of a small controversy. Google (still, AFAIK) offers unit conversion as a part of their search box; you can type a unit conversion into Google and get a conversion done. Some people noted this, wondered about what the backend might be, and typed some stuff in which was known to trigger a then-present bug in GNU Units. And wouldn’t you know it, Google showed the same bug. This was all well and good, since GNU Units uses GPL, not the AGPL (which did not even exist at the time). But then some time later, Google fixed the bug; the unit conversion could no longer be triggered to exhibit the bug. But no fix for GNU Units was forthcoming from Google. At the time, this was surprising and cause for some hullabaloo, since Google was still ostensibly in their “Don’t be evil” stage.

(Disclaimer: I only heard about all of this via the rumor mill; some details may be wrong or omitted.)