By some laws, such as Title III of what was called the Safe Streets Act of 1968, law enforcement agencies are allowed, under certain carefully restricted circumstances, to attempt, without guarantee of success, to penetrate the private communications of citizens through wiretapping. If a law enforcement agency encounters an encrypted communication or file, it is not prevented from employing every resource at its disposal to perform cryptanalysis. The FBI operates a cryptanalytic bureau (originally in Washington DC, according to Kahn), for this purpose.
This yields a balance. Neither side in this potential conflict has been given the right to succeed. The situation remains in the grey area between two extremes.
If citizens were to be given the legal right to succeed and therefore have absolute privacy, law enforcement agencies would be required to stop attempting to penetrate citizen privacy lest they accidentally succeed and therefore violate a citizen's right to have absolute privacy.
If law enforcement agencies were to be given the legal authority to succeed and therefore have absolute invasion of privacy, citizens would be required to stop attempting to keep communications private lest they accidentally succeed and therefore violate the agency's authority to have absolute understanding of any wiretapped conversation.
Since the real world is not black and white, this should not be an issue. However, Law Enforcement and National Security forces in the Executive branch have been trying to acquire a guarantee of success for several years now.
I can try to imagine the view of a law enforcement officer, a civil libertarian and a citizen in court. However, I can state definitively only my own view.
The former might be prudent. The latter is an attribute of a police state, in which the normal citizen is treated like a suspect or enemy (as we saw in the former Iron Curtain countries) or like a prisoner whose cell must always be available for surveillance. Prisoners aren't being watched continuously. They have moments of privacy. However, it is entirely the guard's decision when a given prisoner is watched or enjoys privacy. The prisoner is not allowed to act to achieve privacy of either communciations or records.
Living in a free country rather than a police surveillance state is important enough to me that I would gladly vote to let criminals frustrate the FBI's desire to wiretap rather than submit the entire population to what amounts to an electronic strip-search here in cyberspace. Of course, I have had experienced law enforcement officers explain to me that criminals, by their very nature, believe they are invulnerable and would never be so prudent as to use good cryptographic security. A spokesman for the FBI itself has confirmed this level of criminal hubris. But even if that were not true, I would still vote to frustrate the FBI rather than submit my fellow cyberspace residents to enforced search.
The list of quotes has grown enough that I moved it to a separate file.