Billionaire Kelcy Warren, who faced months of protests over the Dakota Access oil pipeline, said his company followed every law and still fell into a “mess.” Warren “underestimated the power of social media” during the standoff with environmental and Native American-rights activists, he said on a call with analysts Thursday. The Energy Transfer Partners LP chief executive officer was surprised that people were able to spread messages — including falsehoods — so widely and quickly over the Internet and “get away with it.” “There was no way we can defend ourselves,” Warren, 61, said on the call. “That was a mistake on my part.” For months before the Trump administration cleared the way for construction, Dakota Access was a flashpoint for opponents of fossil fuel projects and others […]