Philip Morris USA is suing two Internet-based cigarette vendors, alleging their operators are infringing on company trademarks by illegally importing Marlboros and other brands made for foreign markets and selling them in the United States. Philip Morris USA filed the two lawsuits against the operators of www.paylessmoke.com and www.cigmall.net, along with other related Web sites, in U.S. District Court for the Southern District of New York.