WASHINGTON, April 1, 2014 (GLOBE NEWSWIRE) -- CoStar Group, Inc. (Nasdaq:CSGP) this week is filing a series of lawsuits against 8 real estate firms and individuals as part of a coordinated anti-piracy campaign aimed at ending theft of CoStar services. The suits allege systematic theft of CoStar's services though acts of online piracy and computer hacking via illegal password sharing. The defendants in these cases could be ordered to pay millions of dollars in damages. CoStar is also filing a "John Doe" lawsuit in New York federal court based on allegations of improper use of CoStar data and photos to populate a competing service called CompStak. To move the case forward against named defendants rather than John Does, CoStar seeks to compel CompStak's disclosure of the identities of its users that have allegedly violated CoStar's copyrights. CoStar builds its products and services at significant expense and, accordingly, must ensure that they are not stolen. Among the defendants implicated in the data theft lawsuits are two Denver real estate brokerage firms co-owned by Chang Enterprises, a family investment company that includes former tennis champion Michael Chang. The complaint alleges that the two firms, Dunton Commercial and SullivanHayes, were responsible for 2,259 unauthorized logins to CoStar's networks over the course of several years. Additional lawsuits have been filed against Detroit-area based Insite Commercial Group and its principal, Randall Thomas; Dallas-based Chris Chevreaux d/b/a Chevreaux & Associates and Ben Dyess d/b/a Ben Dyess & Associates; and Chicago-based Richard Griego d/b/a Frontera Realty Consultants, who in aggregate are alleged to have illegally accessed CoStar's services thousands of times. CoStar has also filed suit against a Los Angeles-based individual, Andrew Gee, alleging that he engaged in blatant and widespread misuse of CoStar's services in connection with his attempts to launch a competing commercial real estate information service, PropertyDeets.com. Gee was formerly an acquisitions and asset manager with Meridian Property Company before leaving and starting his own business in 2013.