Infringing Economist ads and the right of attribution

I've been having a recurring argument lately about the morality of "attribution" and how bad it is to make money off of someone else's creation. But take this (terrific) Economist ad (the ads in London are about 1000x more clever than their American counterparts, and about 10x more clever than their Canadian cousins). It is clearly making money off of Scrabble, so should it give them a cut? How about attribution? "The Scrabble tile and Scrabble are Registered Trademarks of Hasbro, Inc."? The whole point of the ad is that there's no text EXCEPT the text on the tiles; it would, IMO, substantially weaken this piece to add an attribution line. Should they have to, anyway? This is what Lessig means when he talks about If Value, Then Right thinking. If there's some value in something, then someone must have a right to it. But would giving Hasbro a piece of the action encourage Hasbro to make better games? Will not giving them a cut discourage them from making more games in the future?