Triangulation is probably one of the worst scams to be found on ebay.

The term triangulation is used because the scammer sets up a "triangle" consisting of three different victims.

In the first part of the scammer's triangle is victim number one. The scammer has somehow obtained victim number one's credit card information, which the scammer will use in perpetrating the scam.

Victim number two is most often a large online store, one such as Amazon.com or Walmart.com.

While victim number three is the winning bidder of the scammer's fake auction (more about fake auction below). Victim number three is the victim who suffers the most as a result of this scam

Essentially the scam is set up as follows:

The scammer sets up an auction displaying an expensive item (anything from jewelry to clothes to electronics) which can be purchased on victim number two's website (again this is usually a large site such as Amazon.com, etc.)

The purpose of this auction is to attract an unsuspecting buyer (victim number three) into dealing with the scammer.

When victim number three wins the auction he or she sends the scammer payment for the item.
The scammer then uses victim number one's stolen credit card number to make a purchase from victim number two's website.

Victim number two then sends the purchase to victim number three's address and the scam is complete.

Within the next few days/weeks, victim number one finds the unauthorized charges on his/her credit card and iniates a chargeback.

When victim number two receives the chargeback they soon find out that the credit card used was stolen, and they contact the police to get their money or merchandise back.

Victim number two provides the police with victim number three's address (since this is where the item was shipped) and victim number three is then left without his money, and/or merchandise, and may be investigated for theft.