Speakers and writers who value precision know that the past tense of hang, when it means "to put to death using a rope," is hanged, not hung. This applies to both the active and passive voice: They hanged the prisoner and The prisoner was hanged.
For inanimate objects, use hung. Under unusual conditions, people also hung or are hung, e.g., He hung from the tree with one hand or He found himself hung upside down.