So I should have searched a bit longer, because then I might have found
https://bugzilla.redhat.com/show_bug.cgi?id=961642 which indicates that the Ubuntu Font
License (1.0) is non-free and talks about what's wrong with the license. Amazingly,
it doesn't grant any permission to actually use the fonts.
Still, to head off future questions, could we get it listed as bad in the license list?