First, a clarification. The egg yolks in the center of the moon cakes that prompted your concern, and presumably the concerns of many others (statistically, for every letter written to a congressperson, the government assumes 9, or 99, or some other amount of people feel the same way — and so shall we), are not raw.
Moon cakes contain cooked egg yolks, recalling the shape of the moon. We apologize for not being clearer about this detail.
Also -- Gene's supporting point, regarding mayonnaise and spoilage, got us thinking. We vaguely recall Chef Lars at telling us in our Introduction to Professional Cooking class that mayonnaise keeps for at least a week on the countertop. Now we would never hold him to this in a court of law (for one thing, our brain is a tad unreliable in the memory department, and plus we can't find that advice in our old, yellowing notes), but the thought did prompt us to take a wander around the Internet on the topic, where we found this NPR feature, debunking the myths about mayonnaise on its 250th birthday.
SFist Julie, contributing. After the jump, the truth about mayonnaise, and the dreaded.... potato salad!