Never pay down a deposit in a bank account until you have met the seller, seen signed a purchase agreement.
No serious private advertisers ask for a down payment before you meet.
Receiving an email with an in-scanned ID does not mean that you have identified the sender. You do this on the spot, when you sign a purchase agreement.
J. Cassidy - How Markets Fall. A serious book about the structure of modern American capitalism. It also describes the history of its development and the causes of the crises of the lot and in 2007.