How do you feel about FBI undercover operations on Facebook, LinkedIn and the like?

An article on MSNBC pointed out that the FBI and other justice organizations make fake profiles on social networking sites to gather information about suspects. They “friend” people and then go through the files the suspect has posted. There is currently no outside regulation.

Now there are two main sides to this. It is a rather effective method for capturing thieves, child molesters etc. They can see if what offenders tell the police matches what they tell their friends. At the other end of the specrum, there is the side of privacy invasion. How would you feel if you new your new facebook friend was really an undercover cop? It seems a bit invasive.

The entire method of undercover investigation is a controversy. What position do you take?