Should they also post warnings about not eating certain types of fish (ciguatera), not swimming in fresh water (leptospirosis), not eating raw meat or fish, not leaving food out for extended periods of time, etc., etc. Where does personal responsibility come into play?   Personally I'd never leave a drink outside and then drink it 12 hours later. Nor would I buy anything from a roadside stand that wasn't cooked right in front of me. Common sense goes a long way.