CAPTCHAs can FOAD.
Tests designed to weed the Humans from the computers are often difficult if not impossible for the Humans to solve, yet obscenely easy for the Computers to thwart.
Audio tests that can't be heard by anyone without (perfect) hearing, yet a Computer can filter out the background hiss/cracks/pops/crap to get the code to be repeated.
Visual tests that can't be properly (or at all) seen by anyone without (perfect) vision, yet the Computers can pick out the bits they need in less time than it takes a Human to even focus on the image in the first place.
And when the Human fails to get the answer right the first time in the few seconds allowed, we're given a new test to try again... and again... and again... all while the Computer snorted in amusement, handed over the answer, & got past the tester's desk without even breaking stride.
This is the exact opposite of what the test is supposed to do, yet it's the Humans that get the shaft for our all-too-Human failures.
Thank you for those CAPTCHAs. I hope you choke on them & die.