In practise I've never had any use for guest; never allowed anyone to put anything into a guest schema; never allowed guests to do anything; so of course I didn't know the answer (and suspect that I'm not in a minority in that approach to the guest user); but got it right by common sense reasoning, not by random guessing.

Maybe what's disturbing is that so many people guessed wrong, on something which seems to be very easy to get right by thinking about it a bit, even if one doesn't actually know the answer?

My reasoning is that (apart from owning the guest schema) guest by default has no permissions other than connect (and that is something which everyone must surely know?) so he can't see anything other than the guest schema (and presumably its contents, if any). However, there may be something illogical about that reasoning, perhaps it's just a lucky (for my point score) accident that it leads to the correct answer correct answer; and it could be that "Arturius"' reason for finding it disturbing is something altogether different.