Daniel Ringmaiden, a convicted tax fraudster, exposed the Stingray, the device that tracks down the location of cellphones.
And in the process, he discovered that the technology had already been around - and kept secret - for 20 years. It was used by the federal government and spying agencies for 12 years, before being released to law enforcement.
And even after he exposed the device, it was two years before news of it went mainstream, and entered the public consciousness.
So these neat little toys? You should assume they have been around, and in active use, for quite some time.