Google Inc. has filed a federal lawsuit seeking to block groups it called "rogue online pharmacies" from advertising Viagra, Cialis & other prescription drugs on its search engine and websites. The move comes as Internet companies continue efforts to prevent fraudsters from preying on their customers, potentially keeping them from doing business with legitimate online operators. "Rogue pharmacies are bad for our users, for legitimate online pharmacies and for the entire e-commerce industry—so we are going to keep investing time and money to stop these kinds of harmful practices," Google lawyer Michael Zwibelman wrote in a blog post Tuesday. In a complaint filed Tuesday in U.S. District Court for the Northern District of California, Google alleges one individual and 50 unnamed defendants "violated policies and circumvented technological measures" by using its Adwords online-ad program to promote pharmacy and prescription-drug operations without being verified by the National Association of Boards of Pharmacy. In doing so, the defendants broke a contract with the company, Google said. Google, facing exponential growth in the number of advertisers purporting to sell online drugs, prohibits the promotion of such products and services except under certain conditions, such as verification by the pharmacy group. The suit comes as the so-called rogue pharmacies have continued to attempt to use AdWords with increasing sophistication, Google said. Adwords is a self-service system that places ads alongside relevant search results. Google's action came the same day eNom Inc., a large provider of Web addresses, agreed to work with LegitScript LLC, an Internet pharmacy verification service, to crack down on websites that knowingly host illegal online pharmacies.