what shall I do?

[Alfred M. Szmidt]

   Perhaps someone from the FSFE could have an eye on the case and
   talk to them again.

Only the copyright holders can do anything leagally.  And since you
noted that the copyright holders didn't care, you're out of luck.  If
they copyright holders just don't care, then anyone can do essentially
what they want.

This is why it is so nice to be able to assign the copyright over to a
central source that cares about license violations, and will kick some
ass. :-)

Cheers.