Netflix is moving to protect itself against hostile takeovers, less than a week after activist investor Carl Icahn disclosed a stake of nearly 10 percent in the online video company. Netflix Inc. said Monday that it has adopted a shareholder rights plan, also known as a poison pill. Such a plan is designed to make it difficult or even impossible for someone to take over the company without an agreement from the board. When the provision is triggered, additional shares flood the market and make it prohibitively expensive for a takeover.