What flavortexts are allowed?

The design team asked for suggestions for flavortexts for the next set. What flavortexts are allowed?

BenPeal wrote:

Quotes from World of Darkness books and anything that is public domain. Avoid non-WoD material that is copyrighted.

So, quote from "Book of Nod" = ok?
Quote from Winston Churchill = ok?
Black Sabbath lyrics = not ok?

Squidalot wrote:

Yes - but it also needs to be card specific and take into account space on a card - therefore as such more appropriate to take place in the playtest forum on or on the facebook page Henrik!

Ah, missed that bit. Most of my suggestions would be pretty unspecific anyway, but I´ll try to think harder!

But my question was also a bit more open I guess, regarding US laws and what really happened when the quotes on Vtes cards went from pretty awesome (Jyhad), to pretty boring (all other sets). Did Black Sabbath actually sue WW for quoting them on Faceless Night? Or was it David Lynch that got pissed about Owl Companion?