In order to prevent theft and other crimes from happening, the Xi’an Party Committee and the government decided to install these monitoring systems on more than 4,400 public transportation vehicles. Meanwhile, it is also considered a measure to ensure social stability during the 60th Anniversary celebrations. This is part of a larger Public Transportation Technological Safeguard System. The system is a required element to protect public safety.
Source: China Economy Net, September 23, 2009.
http://www.ce.cn/xwzx/gnsz/gdxw/200909/23/t20090923_20081637.shtml