Automated face analysis will find many applications may be its entertainment, home automation, medical or educational. While technology is getting advanced, hope its not use for wrong things. If it does get misused our policing laws and procedures also need to get advanced at same speed.
I suppose I could see face recognition technology being used to violate the privacy and security of ordinary citizens. More likely is the Minority Report type of scenario where it becomes completely normal for it to be somewhat invasive in the way it targets individuals for marketing and other purposes. At that point, the government and the police and other authorities will not stand in the way.