Empty Wine Glass

"A word o' caution for all ya land owners. If'n you find an empty wine glass at yer front door, fill it wit wine n' consider it an offer'n. Lest you be dealin' with them... party-ers..." - Old Jib

As the story goes, in some parts of the Olympian Isles, finding an empty wine glass at your front door means more than a simple case of littering. It is seen as an ill-omen to those who do not know its true meaning and you can counter its bad luck by filling it with an offering of wine and leaving it be. In a short amount of time the glass would be taken and that would be the end of it.
As it turns out, the empty wine glass is a symbol used by followers of Dionysus. Predictably, these crazy debauchers run out of suitable spaces to throw their crazy ritual parties. When such an occasion arises, the followers venture off into prospective manors and leave an empty wine glass at the front door. When they return, if the wine glass is full, they see that as a polite refusal and an offering to Dionysus. If the wine glass remains empty and in the same place, then the place is poor or abandoned and may be a good place to party. If the wine glass is missing or broken than that is seen as an acceptance of being a venue for one (or more) of Dionysus' parties.
For the unfortunate few who have been unwary victims of the empty wine glass, Dionysus' parties have been known to lasts days or weeks and cause complete destruction to all but the most wealthy or the most prepared.

Significance

As the god of wine, Dionysus views wine glasses as something close to a holy symbol.