So, if I download the #Rust logo from the Rust foundation's site today, it is licensed under CC-BY, which allows adaptations. Can the Rust foundation actually revoke the license of the file I already have a copy of?
Of course, IANAL, and the threat of a lawsuit would be enough to make me stop, but it feels like legally this feels like a "can't unring the bell" situation.
@ecton
IANAL, the following are just my understanding of trademark and copyright laws in the US.
Trademark and Copyright are related but separate issues. As seen from Monster Energy's lawsuit with Glowstick Entertainment over the "Monster" in a game title, in a trademark dispute the material at dispute does not even need to be an adaptation of any copyrighted materials. Even though the CC-BY license allows adaptations, it is only a copyright license. As long as Rust(tm) is a trademark, Rust Foundation HAVE TO go after usages of the logo which may mislead audience about Rust Foundation's involvement. I suppose that is partly why Adacore and Ferrous Systems are giving their verified Rust toolchain an entirely distinct name, Ferrocene, instead of VerifiedRust or something to that effect. (Ferrocene being a better and cooler name notwithstanding.)
For example, Adacore website has a Legal section which specifically attributes trademarks such as HP-UX, Java, and Mac to their respective owners as well as a general attribution for the ones not specifically covered.
