As online attacks grow in volume and sophistication, the United States is expanding its cybersecurity efforts. Threats come from both criminals and hostile countries, especially China, Russia, Iran and North Korea. They aim to spy on and disrupt American businesses and government. The CIA has created a directorate to improve cybersecurity and conduct cyberespionage, and the nation’s top spy wants the country to be even more aggressive. The United States already conducts massive online spying and was recently discovered to have embedded surveillance and sabotage tools in U.S.-made computers and networks used in China, Russia and elsewhere. Meanwhile, high-tech companies are building powerful privacy protections into their consumer electronics, to the dismay of law enforcement and espionage agencies that fear these efforts will harm their investigations.