Someone calls, e-mails, sends a letter, pretending to be a family member stuck in a jam. They say that they are in jail, the hospital, or there car won't start and that they need you to wire them some money right away. Sometimes there might be a second person pretending to be an authority figure in order to make the scam seem more realistic.
How to prevent this scam
If someone calls claiming to be a family member, you can ask them questions that you know for sure only that family member would know. Or you could ask them about the rest of the family.