Dogs can find non drug and possible prohibited produce...
.
a)
Dog Handler here.
I can train any dog to 'flag' at my signal... irregardless of the walk-around producing any reproducible/verifiable indicators.
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I worked in three penitentiary settings.
Working inspection dogs in that environment was for intimidation.
Zero to do with locating contraband.
.
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b)
In California, the bug-shack uniforms --
for other than commercial rigs -- rely on voluntary 'self-reporting':
Meek traveler, meekly holding half-ate snack -- "I bought this tuna sandwich at the Wal*Mart in Winslow Arizona, such a fine sight to see..."
Authority Complex drone -- "Confiscate!, Confiscate!, everybody must comply!, Rules!, strict Rules!, Confiscate!"
.
Nincompoopery.
Winds aloft carry Afrikan spiders to Antarctica, Asian cockroaches to Hawai'i.
I have zero confidence in some arbitrary scrawl scribbled on a paper map as a barrier to stop airborne bugs in Arizona/Baja/Nevada from migrating to California.
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If, on the other hand, their intent is intimidation, how would you rate their success?
Wait, we don't need to rate them, their press-release tells us everything we need to know.
[sarc]