The potential for encroaching software licenses is the motive behind pure freeware distributions; I would note here that the gNewSense distribution is based on Ubuntu, but with all problematic items removed.
It is available at http://www.gnewsense.org/static/homepage/
for users of Fedora, the equivalent free distribution is blag, available at http://www.blagblagblag.org/
We should encourage and support these efforts, to preserve the freeware ecosystem.