Sometimes a place got a bad reputation for a reason. It may look safe to you because you don't live there, and don't have the connection with the local people as people from Hong Kong or Macau do.
I stayed in China for 2 years before coming here. Even the Chinese think Guangdong is one of the most dangerous places in the country. Everyone in China knows that some places in Guangzhou (anywhere near the train station for example) and Shenzhen (some areas in the subway) are not somewhere anyone should spend any time to linger around because of the organized crimes.
A colleague from China just sent me 2 links and warned me to be extra careful when I go back to the factory.
I don't know what the report says, but it is scary enough just by looking at the pics. I was told a total of 28 people were arrested and everytime a few of them would wait for a prey at a bus stop during the daytime, attacked the victim with something like a brick and grabbed all his belongings! They have been doing that for months, sometimes 3 times in an hour! This is only one of the things my colleague from China warned me about. (Others include the use of a mobile phone shaped electric shocker and they will fry the victim alive, take his belongings when he is unconscious.)
If the local people tell you to be careful, trust them! They probably know more than you do, no matter how many times you have visited a place. Common sense simply won't get you out of trouble in this kind of situation and the people around you are not going to save you! Any place can be safe before something bad happens to you.