The FBI paid $1.3 million to hack into the San Bernardino iPhone. This is after Apple refused to open up the iPhone, after the FBI could not access it by brute force due to the security features implemented by Apple. From the Washington Post:
Federal authorities have not publicly revealed who helped the FBI unlock the San Bernardino iPhone, which was at the center of an extended fight between the government and Apple. The Justice Department had maintained that only Apple could help it access the phone without erasing all of its data before abruptly saying it had gotten help from an outside party and no longer needed Apple’s assistance.
According to people familiar with the issue, the FBI cracked the phone with the help of professional hackers who were paid a one-time flat fee. Law enforcement officials have said recently that the FBI has found no links to foreign terrorists on the phone, though they are still hoping that geolocation data on the device could help reveal what the attackers did during an 18-minute period after the shooting.