Hasbro, which owns the right to the game Scrabble, has filed suit against the creators of the hugely popular Facebook application Scrabulous.

The suit names Rajat Agarwalla and Jayant Agarwalla and their company as responsible for intellectual property theft.

Hasbro has already asked Facebook to remove the application, which has over half a million daily users and a fan group of nearly 40,000.

Hasbro's own Facebook version of Scrabble has barely 10,000 users and around 5,000 fans.

"Hasbro has an obligation to act appropriately against infringement of our intellectual properties," said Barry Nagler, general counsel for Hasbro, in a statement.

"We view the Scrabulous application as clear and blatant infringement of our Scrabble intellectual property, and we are pursuing this legal action in accordance with the interests of our shareholders, and the integrity of the Scrabble brand."

The timing of the legal action is interesting. Scrabulous has been on Facebook for almost 18 months, but legal action has only begun now that there is an official Scrabble application on the social networking site.