I'd take a chance on:
Actually, it's NOT a legal tactic. Courts have ruled that domain registrars can require a registrant to give up a domain that is purposely misleading if it uses a known company or personal name.
There are a number of celebrities who have sued over this, and I think that one of the main court cases came from one of the two major SAT prep companies having registered their own domain, as well as a domain for their competitor, and set up web sites for both. For their competitor's site, the had nothing but complaints about the training and service. The courts ruled that they had to give up the domain.
Most registrars have as one of their terms of service that you must give up the domain if they believe that the "fair use" of the domain name is not in good faith.