Our system goes a little further and we've had pretty good success with it: send them a link beforehand where they can enter the bug. Make the important fields required and don't accept bug reports any other way. Some of the users then just stop sending in bug reports and some fill things in with meaningless information, but generally the quality of the reports went way up.
The theorems suggest that Tautology is a good candidate for an interesting set not in [P] and I feel it is worth spending considerable effort trying to prove this conjecture. Such a proof would be a major breakthrough in complexity theory.
Locks? What are those? Do you mean password protected? Yeah, I have that.
Real Users find the one combination of bizarre input values that shuts down the system for days.