Topical
Forty-four years later, the electronic surveillance of the type shown in this movie, i.e., that which is done without legal cause nor justification, has come to fruition right now with the telephone record 'data mining' of the NSA.
Even more ominous and sinister is the widespread use of a covert cellphone intercept and tracking device known as 'stingray' of which at least 53 police departments across the United States possess, yet no one knows how often it's used because the suppliers of the device (the federal government) has stipulated that a condition of its usage is that it will 'never' be revealed (nor even acknowledged to exist) in any court case.