... The FSF would be against GPLv3.
Imagine: some software/music, say GCC, is released/distributed under GPLv2. People can do whatever they want with it: redistribute it, reuse it in their own source code/music, or whatever. Then GPLv3 comes out. Suddenly the software/music won't work on/play in your hardware/software.
How is this different from DRM?
The FSF has gone so far to fight against DRM that it has created some of its own. In my opinion, this is the same mistake Lenin made: a far right totalitarian regime was replaced by a far left totalitarian regime.
Viral licenses are incredibly dangerous because they put someone like the FSF in charge of something they didn't write: imagine Linux without the GNU utilities. So RMS, who wrote some section of the code, controls the whole.
I really hope this isn't true, so if someone disagrees please comment extensively.