Should law enforcement officers ever use deception in their efforts to root out crime and bring criminals to justice?

Pro: Criminals, by definition, operate outside the law. Unless some arm of the state is authorized to operate without the constraints of certain regulations in pursuit of criminals, law-abiding citizens are at risk of losing their rights, and a society may be at risk of disintegration.

Con: Law-enforcement officers, as members of a society that respects or should respect the law, do not or should not operate outside the legal and moral restraints that govern all other individuals.