The StingRay is an IMSI-catcher, a controversial cellular phone surveillance device, manufactured by Harris Corporation. Initially developed for the military and intelligence community, the StingRay and similar Harris devices are in widespread use by local and state law enforcement agencies across the United States and possibly covertly in the United Kingdom. John McAfee explained the system to CNBC earlier today and said that the FBI could implement such a system in the future and bypass encryption in a heartbeat. It's a fascinating revelation, but that's a solution that could be adopted in the future.
In the short term, McAfee knows who the FBI is working with for the workaround for the unlocked iPhone 5c and he noted that: "I promise you that [Apple CEO] Tim Cook and Apple are not going to be happy with the solution that the FBI has come up with, Because it is almost as bad as a universal master key."
Update Mar 22, 2016 7:30 a.m. PST: See our follow-up report: The FBI is Reportedly Working with an Israeli Firm to Unlock the San Bernardino iPhone 5c