Meanwhile, porn artists produce and distribute collections that blatantly use Hasbro's trademarked characters (albeit usually humanized). For monetary gain. With no visible indication of lawyers breathing down their necks.
There is no justice in this world.

They dropped the hammer on a non-profit project that was being done purely as a tribute to the show and the fans. They then proceeded to use the background of the Twilight's Library stage as part of a facebook promo.

Merely because it was "technically within their legal rights" doesn't automatically make what they did "right" by definition. It was still a dick move.

…That being said, the inclusion of FiM characters in the next Smash Bros. game would almost be enough motivation for me to get a Wii U in itself.