Stingrays were being used as early as the 1990s by federal law enforcement. They were used to help locate Kevin Mitnick in North Carolina.

Edit - I recall reading that years ago in Tsutomu Shimomura's book 'Takedown' (published in 1996). Outside of this, I have no other reference. It's a good read BTW. https://www.amazon.com/Takedown-Pursuit-Capture-Americas-Com...

I really enjoyed Ghost in the Wires (basically Mitnick's bio). I had first read Takedown by Tsutomo Shimomura which told of Mitnick's pursuit by the guy who ended up help to catch him. "Wires" was the other side - what Mitnick did when he was on the run - and his side of how he was finally caught. Really interesting stuff. It was like the Rashomon effect[1].

http://www.amazon.com/Ghost-Wires-Adventures-Worlds-Wanted/d...

http://www.amazon.com/Takedown-Pursuit-Capture-Americas-Comp...

[1] http://en.wikipedia.org/wiki/Rashomon_effect