One can't expect privacy on a phone call if they asked an operator to connect them. DNA couldn't be considered private if someone left it behind. If a camera has a zoom lens that can be used from a public area to learn a little more about an individual in their private area, that's hardly an invasion. With each new technology that is introduced, our expectations of privacy become less reasonable.
Former head of the National Security Administration, Michael Hayden, once argued that if anyone knew and followed the fourth amendment it was the National Security Administration, and nowhere in the fourth amendment does it say anything about probable cause. One may consider it an encouraging sign that he is no longer the head of the NSA or the CIA, unless they take into consideration the Supreme Court's view of the fourth amendment.
In a recent 5-4 decision regarding strip searches in minor offenses, it appears the Supreme Court does not wish to uphold the 4th amendment. Ruling in favor of the system, they claimed "who are we to second guess the police?" They have also brought to our attention that some well known terrorists had minor offenses before they were deemed guilty of major ones. Look at Timothy McVeigh; he was caught driving without a license plate. One might consider an attempt to disguise one's identity as probable cause. In the case of one who carries with him papers stating the warrant is not valid, because he has become accustomed to being arrested for something that is invalid, is his case really comparable to a serial killer attempting to hide is identity? The Supreme Court says "Yes."
Perhaps it is time to rewrite the fourth amendment of the constitution. Our nine justices can sign their John Hancock's to it, and then place it on display within the Museum of National Archives. The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall [word omitted] be violated, and no Warrants shall issue, [section omitted/new add - without the signature of a county clerk].