At the outset, we must distinguish between identification and authentication, which are related but quite different. To identify a person is simply to say this person is Mary and not Martha.

“One pigweed in the field is one pigweed too many.” That’s the heartfelt conviction of North Carolina farmer Landon Moore. “It’s so competitive; I’ve seen it take fields out of ...

“Farmers, for the most part, are doing what the experts are telling them and taking a ‘zero tolerance’ approach to pigweed, but it also includes killing everything else.” Smith farms 3,000 ...