One might like to assume that when the framers of the Constitution sat down to consider the rights and freedoms most deserving of being explicitly put forward in the document, people's right to privacy would be at the top of a short, fundamental list.

Or not. The fact is, a careful reading of the document will reveal there is no constitutional right to privacy.

Did the founding fathers consider such a right so obvious and undeniable they thought it did not need an explicit expression? Or did they not think such a right could be institutionalized in any workable fashion?

What is clear is that they could have no way of predicting the impact of future technologies on personal privacy.

It is difficult to imagine what the convention delegates would have made of a smartphone and the term "text message" likely would just have suggested a written letter, with its privacy taken for granted.

In recent times, though, text messaging and our assumptions about its use have found their way into the very heart of the debate over personal privacy versus national security.

The latest skirmish in that conflict surfaced last week when some law enforcement officials floated a proposal that would require wireless providers like AT&T, Verizon Wireless, Sprint and others to record and store customers' text messages in case police decide to obtain them at some point in the future.

"Billions of texts are sent every day, and some surely contain key evidence about criminal activity," Richard Littlehale from the Tennessee Bureau of Investigation testified in front of the House Subcommittee on Crime, Terrorism, Homeland Security and Investigations.

"In some cases, this means that critical evidence is lost. Text messaging often plays a big role in investigations related to domestic violence, stalking, menacing, drug trafficking, and weapons trafficking."

Technology firms and privacy groups are urging Congress to update a the 1986 Electronic Communications Privacy Act for the cloud computing era and the committee has been taking testimony on what that upgrade should include.

The law, updated in 1994 and in 2001, covers how government agencies can conduct surveillance and under what circumstances they can demand information from organizations and individuals.

If law enforcement agencies succeed in attaching a text message retention requirement onto any proposed new version of the ECPA it is likely to complicate debate over such a measure and erode support for it among privacy advocates and the Silicon Valley tech companies lobbying for a rewrite

There is no consistent policy among wireless providers regarding retention of text messages.

As of 2010, AT&T, T-Mobile and Sprint did not store the contents of text messages; Verizon did so for up to five days and Virgin Mobile kept them for 90 days.

Richard Salgado, director of law enforcement and information security at Google, acknowledged to the committee the ECPA needs upgrading to keep pace with technological developments and capabilities but argued it must maintain the public's privacy expectations.

"ECPA frustrates users' reasonable expectations of privacy," he said in prepared remarks. "Users expect, as they should, that the documents they store online have the same Fourth Amendment protections as they do when the government wants to enter the home to seize documents stored in a desk drawer."

The Fourth Amendment addresses "unreasonable search and seizure" but not privacy as a fundamental right.

That's something the Constitution is silent on; the word privacy appears nowhere in the document.

Which is why the public and, as of last week, the Congress are still struggling with the concept of privacy, as advancing technology makes it ever more tenuous but perhaps more deserving of protection than ever.

It remains to be seen what a revamped Electronic Communications Privacy Act might contain, how it might affect the public, what it would protect and keep private -- or not protect and not keep private.