Kristian: Why is that? Is anyone claiming to own the very concept of a "mech"?
Strijkbout: I don't know the details but Mechwarrior 5 was cancelled because of it, I think it was claimed designs were stolen from Robotech or some other Japanese mechfranchise.
Some more details about the issue here:
http://www.sarna.net/wiki/Unseen#Super_Dimension_Fortress_Macross In short, FASA licensed the designs to the VF-1 in SDF Macross from an American distributor. Unfortunately that company apparently didn't have (either full or in-part) the rights to license them out to FASA in the first place. Our of the resulting legal melee, FASA reliquished the rights to use those designs.
On top of that has been Harmony Gold USA pursuing aggressive legal action against anyone and everyone who's released anything who seemingly may even have a tangential relation to Macross. It's gotten to the point where they claim to have
unlimited international ownership of Macross, even though (a) the Japanese company who sold them the rights themselves may not have been legally entitled to do so, and (b) Japanese courts ruled that Studio Nue, the original series creators, are the true owners of the Macross IP.
Naturally, Harmony Gold USA's response seems to amount to "Fuck You" to the Japanese.
Presumably this is to choke off any distribution of the Macross series or IP outside of Asia, so they can push their own highly lucrative Robotech franchise. What makes this all the more galling is that their "franchise" basically creatively leeched off of the talent behind three completely different anime series.