This simply isn't true, so I recommend you double check with your textbooks and maybe your professors. The best example here is, in fact, Xerox, who spent millions of dollars "educating the public" so that their name doesn't get genericized. Granted, Lone Wolf is nowhere near at the same level of common use as Xerox so the analogy is crap, but Xerox is definitely the prime example of a successful defense. Counter examples of companies NOT taking the appropriate action to fight genericide are cellophane (DuPont), escalator (yes, originally a trademark), and lite beer.