Protests are being held across the country today calling for a single-payer healthcare system. Demonstrations will target the headquarters of several health insurance companies, including Blue Cross/Blue Shield, Aetna, Humana and United Health Group, as well as the annual convention of the insurance industry lobbying group America’s Health Insurance Plans in San Francisco. Malinda Markowitz of the California Nurses Association said, “We are calling a national protest against these insurance companies, because they profit by denying care to our patients — not by providing it.”