MID codes are not "owned" by anyone, they are part of a cooperative effort between media makers and hardware makers to identify media. However, a media maker may well make a case that there is some "implied ownership" resulting from the use of these codes. The biggest issue would be with advertising that the media carries the code or mentioning the TY name in any context.
Personally, I would be glad to see TY go after anyone selling fake TY media, but I seriously doubt they would be successful unless they happen to have a corporate presense in the country where the offense is occurring.
I also doubt that a seller of fake TY will get a lot of moral support around here.