My favorite were the old age verification systems. I remember my dad had the original? Leasure Suit Lary, and you had to prove you were both authentic and of age.

Authentic: enter the 5th word on page 7 of the instructions (easily foiled by a copy machine)

Of Age: who won the 1978 World Series? What is a 6th grader to do there? Phone an uncle? Go to a library or book store? I breakable... Pre internet anyway :)