Getting more dangerous in China

I am a US Citizen visiting China, today I had some friend over from Hong Kong and we took them to the Lo Wu Commercial shopping mall by the border and I was beaten up with fists and kicking me by like 5 or 6 of the store clerks at the shopping mall by the Hong Kong Border. I was beaten up by them because I did not want to buy the wireless transmitter and said I wanted to think about it, my mouth and arms are hurt with minor injury so I am OK. So for the next 3 hours I had to sit at the police station and file the report, which ends up probably nothing happened to them. China is getting more dangerous and we need to be careful not to get into trouble. Of all my years (all 18 of them) here, I have never encounter such experience, and certainly never expected to happened in "civilized city like Shenzhen". Can you send me some links to the travel sites that I can write on the forum to warn people about shopping there, as there are more and more foreigners who shops there, and 5th floor that sells all electronics is where the gangs reside, because if one of the clerk started something the rest of the 10 or 15 stores gangs up on you. So I want to be able to warn people about this, and share my experience

 More Shenzhen Travel Reviews

1. A Brief Tour to Shenzhen GREEN from England Feb 9, 2010 18:43

2. One month in Shenzhen BANOSD from US Jan 22, 2010 14:16

3. Shenzhen One Day Trip HELPER from Canada Dec 28, 2009 03:17