To prevent yourself from being scammed, overseas customers must keep the following tips in mind:

Don't try to buy original famous brand such as Ipod, Iphone, PS3 from China. Due to the low labor cost and sound industrial chain, almost all world famous brands have their products made in China by OEM (Original Equipment Manufacture) way, for example Apple's Ipod and Iphone, HP and Dell's computer, Nokia and Motorola's mobile phone and Bluetooth headset, Kodak's digital photo frame, but restricted by law, the factories doing OEM for the said world famous brands never dare to sell the original products to the market without permission. On the other hand, only authorized distributors or franchise shops of the famous brands are entitled to sell their original products, but all famous companies have the same policy around the world, the price at which a Chinese distributor can provide would be as same as that in your country, not to mention the shipping cost, so if a Chinese supplier tells you that he can supply original product with low price, that means he lies to you. Let us take original Ipod as example, in Apple Corporation's official Chinese website: www.apple.com.cn, the cheapest Ipod Touch is RMB 1598 (USD 234) and the cheapest Ipod Shuffle is RMB 448 (USD 65), hence if someone tells you that he can supplies original Ipod products much cheaper than the said official price, you can make your judgment.

Usually in the frauds in international trade, scammers always offer an extremely low quote to lure overseas customers and disappear after receiving the payment. If such misfortune befalls you, you may adopt the following steps (maybe applicable to Shenzhen and neighboring region only):

1. Since you are not in China, so you should immediately report to local police in your country, and get the police send an express letter by UPS, FedEx or DHL to the units below for help:
110 Command Center, Shenzhen Public Security Bureau, 4018 Jiefang Road, Luohu District, Shenzhen. Tel: 86 755 84464050, Fax: 86 755 84464060.
 
CID (Criminal Investigation Center), 15 Dongbin Road, Nanshan District, Shenzhen City, Tel: 86 755 84465595.
 
2. Contact the only English newspaper in Shenzhen area to make this case public:
 
http://szdaily.sznews.com

3. If the case is processed slowly in Shenzhen police, you may consider to contact the mayor and chief of public security bureau to put pressure:
http://www.sz.gov.cn/cn/hdjl/ldxx/