Two categories of preventive tactics to ward off hostile takeovers can be distinguished: a company’s changed status and “poisoned pills”. The former category has a strictly preventive character because it serves only as deterrent for a potential hostile bidder, while the poisoned pills begin to work only when a hostile bidder buys a certain amount of shares. Changed-status tactics can be divided into a dozen categories. They are increasingly used by American public companies. Opinions about such techniques are divided. Some think that they are not in shareholders’ interest.