[deleted]
No, read the notice. It's not from Mojang.
http://www.pcgamer.com/2014/08/21/minecraft-bukkit-team-lead...
Seems like:
1) Mojang implemented EULA some 3rd party bukkit devs didn't like, they decided to stop supporting their Minecraft API software and publically quit the project, announcing the "end" of the project.
2) Turns out Mojang actually owns (or thinks they own) the project because some members of the bukkit team went to work for Mojang and part of the terms was that they would own it(?)
3) One of the external devs files DMCA to spite Mojang(?) citing GPLv3 incompatibility with being shipped alongside non-Free Software.
There's a lot of legal nuance here that I don't have any answers for, like how copyright assignment worked on this project and whether the people who "sold" bukkit to Mojang had the legal right to do so. If they actually did then Mojang (as copyright holder) could just relicense the project under a different license than GPLv3 and make this all go away in the blink of an eye, so I'm kind of assuming they don't own it as much as they appear to think they do.
Would love to hear more about this from someone who pays attention to this stuff because this seems like a fascinating copyright situation.
In any case, this is a really good case-in-point as to why getting copyright assignment from external developers on any FS/OSS project that you run is a really good idea in general.