American toy company Hasbro Inc has allegedly sued the creators of a Scrabble knock-off called Scrabulous. The online game apparently infringed on the Scrabble North-American rights which Hasbro now owns after acquiring the assets of bankrupt Coleco. Also, Hasbro asked Facebook to block the Scrabulous online game, which has attracted some half-million daily users.

Hasbro is apparently angry that, even after releasing an official Scrabble together with game maker Electronic Arts Inc., Facebook users still preferred the knock-off, even though both were free. The lawsuit was filed in U.S. District Court in New York against Rajat and Jayant Agarwalla, the brothers in Calcutta, India, who designed Scrabulous, as well as their company, RJ Softwares.

Barry Nagler, Hasbro's general counsel, said in a statement that the company has an obligation to act appropriately against infringement of their copyrights. Similar attempts have been made by Mattel outside the United States, but backed down due to heavy protests.

Scrabble was designed by architect Alfred Mosher Butts in the 1930s. The game was met with skepticism by manufacturers, and it only became known because Jack Strauss, president of Macy's, played the game on vacation in 1952.

Currently, Scrabble North-American rights belong to Hasbro, while in the rest of the world Mattel owns the copyright to the popular game. It is estimated that around 100 million Scrabble sets have been sold worldwide.