It was reported in a recent article in Governing magazine that several cities across the US are installing audio surveillance systems on their public buses, which has sparked a debate over privacy concerns and whether or not this particular type of surveillance violates wiretapping laws or maybe even the Constitution.

We have grown accustomed to their being cameras recording our movements when we are out and about... when we go to the bank, into a store, and even in places in restaurants and bars.  There are the occasional complaints that these violate our right to privacy, but the counter to that is that we are not entitled to privacy once we leave the confines of our homes.  When out in public these days, anyone can be taking your picture or video and posting it online... and usually we will never know anything about it.  But for some reason we like to make a big deal when organizations and companies attempt to bring about surveillance mostly as a way to curb violence and crime.  Growing up and riding the bus to school, I can still remember when cameras first showed up on my school bus.  But that camera like all the others have remained mute.  There is no audio.  They were only designed to capture actions and not words.  So there in lies the difference between what we come to think of with security cameras and the types of cameras these cities are trying to use.

"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."  4th Amendment US Constitution

As we have basically accepted surveillance cameras as a way of deterring crime, what is it that they expect from capturing audio, as well?  According to the article in Governing, it's to provide safety and to resolve public complaints.  But could adding audio to the surveillance really add anything to what the video camera is already showing?  I guess it's a possibility.  It could easily show that the person that just started beating another was actually being taunted and teased consistently by another passenger.  But is it worth that extra step since the guy that started beating the other is guilty of assault that the video captured.  Does hearing the audio of that person being teased make it any less of a crime?  Not one bit.  So is the audio even worth it then if it would have no direct effect?  As for others that might be plotting something big (i.e. a bank robbery or terrorist plot) are generally not going to be sitting in a public place where they could be overheard by any number of people sitting around them.  So again, it easily takes out the justification for needing the audio.

Footage from video surveillance cameras can be used in court so long as the footage was obtained with a warrant, but could audio be used in the same capacity?  Privacy groups say this could easily fall under wiretapping laws, which technically requires the government to get a warrant first.  In Kyllo v. United States (2001), the court holds that unlawful search and seizure extends to unlawful use of public space in order to gain private information.  Evidence obtained is inadmissible.  However, the Patriot Act gives the government the authority to listen to our phone calls and read our emails if they feel there is a threat without such a warrant, but would the legality of audio surveillance fall under that particular federal law since it doesn't particularly involve those two things?  And it still remains to be seen how that particular part of the Patriot Act doesn't violate the 4th Amendment as well.  But to counter the wiretapping laws, one could argue that in a public space a warrant isn't needed since anyone can overhear anything you're saying, and you cannot make the assumption that the conversation you are having in a public space is private; therefore, it would not fall under the wiretapping laws.

"The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people."  9th Amendment US Constitution

Do we have a right to privacy?  Yes... in our private residences.  The moment we step out the door, we are no longer guaranteed that particular right as we are then in a public space.  We may not like it, but that is the overall simplicity of the matter.  Does that justify that these cities have a right to install audio surveillance with their video on public buses?  Not necessarily.  Just because you are able to do something doesn't necessarily mean that you should.  The people in these cities should be asking themselves how much more audio can give them over just video, and whether its worth the particular investment.  Do they really need to hear our conversations?  How much more can they possibly get from it?  It appears to be moving to the extreme side of surveillance in the name of safety only to have the same results.