Picking your poison” is taking on a whole new meaning in corporate governance these days.

Poison pills—the controversial plans companies adopt to prevent hostile takeovers—are rising in popularity around the world even as they are becoming more rare in the United States, according to a report by the Institutional Shareholder Services.

Jaclyn Jaeger is a freelance contributor to Compliance Week after working for the company for 15 years. She writes on a wide variety of topics, including ethics and compliance, risk management, legal,...