Chief Executive Mark Zuckerberg said Facebook FB, +0.46% "didn't do enough" to prevent the company's technology from being used for harm as well as good, apologizing to lawmakers before two days of hearings. "We didn't take a broad enough view of our responsibility, and that was a big mistake," he said in prepared remarks for Wednesday's House Energy and Commerce Committee hearing. "It was my mistake, and I'm sorry," he said. Zuckerberg will also testify Tuesday to a joint Senate committee hearing, where lawmakers will question him about privacy and the Cambridge Analytica scandal.