When flight crew gets tested for alcohol consumption, that is sort of understandable.
Usually done at the gate, or somewhere in some office at the airport, right?
Well, listen to this....
A few years back a KLM B737 was taxiing out to its departure runway at AMS. It was stopped, ON THE TAXI TRACK, by the police, who entered the a/c and breathalized the flight crew.
Result: clear, no alcohol detected, continue your flight.
The crew was so fed up with the whole thing that they taxied it straight to the first available gate and reported not fit to fly.
Just to give everyone a warning where this all could lead to.
Cheers!