re: nintendo taking money from their fans. where do you stand?

Maybe its not a very apt comparison, but it is kinda like royalties for actors IMO. Yes they were paid up front, but as the company who hired them continues to use that media for profit, the actors are entitled to a share of that. IMO this is fair.
I'm also assuming that is also worked into an agreement somewhere.

I am not educated fully on what Nintendo is trying to do but I wonder if they legally have this right. Is the agreement made at purchase?