Facebook is going after a social-networking site for teachers, dubbed Teachbook, for attaching the word "book" to its name.

The "book" part of Facebook is highly distinctive and most people associate it with social networking, Facebook said in a lawsuit it filed against Teachbook earlier this month. The only reason Teachbook is using "book" in its name is to unfairly benefit from Facebook's popularity, according to court documents.

"If others could freely use 'generic plus book' marks for online networking services targeted to that particular generic category of individuals, the suffix book could become a generic term for 'online community/networking services' or 'social networking services,'" according to Facebook. "That would dilute the distinctiveness of the Facebook marks, impairing their ability to function as unique and distinctive identifiers of Facebook's goods and services."

Selecting "book" was a completely arbitrary choice and "pilfers a distinctive part of the Facebook," Facebook said. Teachbook's services "are the same as and/or related to some of the services provided by Facebook, [and] while Facebook does not object to [Teachbook's] provision of online social networking services, it does object to [Teachbook's] use of the infringing and dilutive Teachbook mark while doing so."

The name "creates a false suggestion of an affiliation or connection between [Teachbook] and Facebook, where none exists," Facebook concluded.

Teachbook is set to launch in the fall and bills itself as a "professional, online community for teachers." Facebook said previous versions of Teachbook's Web site touted itself as a Facebook replacement with lines like: "Many schools forbid their teachers to maintain Facebook and MySpace accounts because of the danger that students might learn personal information about their teachers."

Among the various charges Facebook is pursuing is cybersquatting. Facebook wants the judge to transfer control of Teachbook.com to Facebook.

Other charges include trademark infringement, unfair competition, and trademark dilution. Facebook wants the court to stop Teachbook from using any "word + book" combination for its name, and to force Teachbook to hand over any revenue it might have made from Teachbook thus far.

Teachbook did not immediately respond to a request for comment.

This is not the first time Facebook has gone after a company with the word "book" in its title. Travel site PlaceBook recently changed its name to TripTrace after Facebook contacted the site and said its name was confusingly similar to its own.

Companies using the word "face", meanwhile, might also want to hide from Facebook's lawyers. As TechCrunch pointed out, Facebook is trying to trademark the word "face." CIS Internet Limited, a U.K.-based company, had reportedly been trying to trademark "Face" starting in 2005 for its faceparty.com site, but it looks like Facebook bought the application from CIS in 2008, TechCrunch said.