Cablevision Systems Corp on Thursday sued Verizon Communications Inc, accusing it of falsely advertising to consumers on television, radio and the Internet that its WiFi service is the fastest available. The complaint, filed with the U.S. District Court in Central Islip, New York, accuses Verizon of basing its "fastest WiFi available" claim on new network routers it has been installing for up to $199.99, despite knowing that Cablevision offers the same routers for its Optimum network, free of charge.