Disregarding warnings
Here in this library, next to a couple computers available to query the catalog, a sign reads:
Do not connect your laptop to these jacks. You may loose all data in your computer.
If I wasn’t a computer-savy person, I’m completely sure I would’ve thought: “They’re bluffing.” And then shit happens, because they’re not.
(Oh, but then of course the sign is not 100% honest either.)