First, has HN really fallen so far as to link slashdot of all things?
Second, a quick explanation of the issue, as I have it: Bukkit is a server made by the community to make up for the simplicity of the official server. It uses deobfuscated, reverse engineered java code from the official server, and has never been given the actual source from Mojang. While Bukkit was sort-of folded into Mojang (They own the name, and a few of the developers went to work for Mojang), no one at Mojang is paid to work on Bukkit and they still don't get source access. Now, a disgruntled Bukkit Dev, Wolverness, has thrown out this DCMA request in some sort of retaliation / blackmail attempt.
I haven't been able to find any evidence that Mojang owns a trademark on "Bukkit", or even that such a trademark exists. They apparently don't own the domain name or the hosting accounts. And they don't own the entirety of the source code.
Mojang is definitely claiming they "acquired" some kind of rights to Bukkit, but I can't find any description of what those rights are -- and, for a community project, I don't understand what they could possibly own that isn't public knowledge. You can't own secret trademarks.
Second, a quick explanation of the issue, as I have it: Bukkit is a server made by the community to make up for the simplicity of the official server. It uses deobfuscated, reverse engineered java code from the official server, and has never been given the actual source from Mojang. While Bukkit was sort-of folded into Mojang (They own the name, and a few of the developers went to work for Mojang), no one at Mojang is paid to work on Bukkit and they still don't get source access. Now, a disgruntled Bukkit Dev, Wolverness, has thrown out this DCMA request in some sort of retaliation / blackmail attempt.