Pawtucket, R.I. -- Toymaker Hasbro on Friday filed a copyright infringement suit against the makers of "Scrabulous," a knock-off version of its "Scrabble" board game that counts over 510,000 daily active users on Facebook. The company also served Palo Alto-based Facebook a notice under the Digital Millennium Copyright Act, asking the social network to remove the game from its sites in the U.S. and Canada as soon as possible. The lawsuit names Scrabulous creators Rajat Agarwalla and Jayant Agarwalla, and their company, RJ Softwares, and seeks unspecified damages. Earlier this month, Hasbro launched an official online version of "Scrabble," developed by Redwood City-based Electronic Arts, which is also available on Facebook. "We view the Scrabulous application as clear and blatant infringement of our Scrabble intellectual property," said Barry Nagler, Hasbro's general counsel.