Analysis - Cyberattack exposes lack of required defenses on U.S. pipelines By Timothy Gardner Reuters WASHINGTON (Reuters) - The shutdown of the biggest U.S. fuel pipeline by a ransomware attack highlights a systemic vulnerability: Pipeline operators have no requirement to implement cyber defenses. The U.S. government has had robust, compulsory cybersecurity protocols for most of the power grid for about 10 years to prevent debilitating hacks by criminals or state actors. But the country's 2.7 million miles (4.3 million km) of oil, natural gas and hazardous liquid pipelines have only voluntary measures, which leaves security up to the individual operators, experts said.