New privacy threats have been uncovered by security researchers that could allow every device operating on 3G networks to be tracked. The vulnerabilities could be exploited with cheap commercial off-the-shelf technology to reveal the location of phones and other 3G-capable devices operating on all 3G compliant networks. It was similar, but different, to previous research that demonstrated how attackers could redirect a victim's outgoing traffic to different networks."
http://www.scmagazine.com.au/News/317819,flaws-allow-3g-devices-to-be-tracked.aspx