In 2001, U.S. District Judge David O. Carter determined that California’s anti-SLAPP statute does apply to cyber-SLAPPs. (See Global Telemedia International Inc. v. Doe et al., 132 F. Supp. 2d 1261 (C.D. Cal. 2001))
In 2003, the Massachusetts Appeals Court cited that state’s anti-SLAPP statute in throwing out a libel lawsuit against a Web site operator whose posted statements suggested a town official was a Nazi. (See MacDonald v. Paton, 57 Mass.App.Ct. 290 (2003) and "State appeals court rules online libel suit was really SLAPP.")
Other state anti-SLAPP statutes may also apply to online libel suits. See "Anti-SLAPP statutes: state summary" for a state-by-state list.