National attention to the Petraeus affair is driven by everything from morbid curiosity to concern for national security. But for most of us, issues of privacy and the First Amendment also should take center stage.

As shown by the FBI's relatively quick trip through the online missives of Gen. David Petraeus' trysts, not much -- if any -- of our electronic communication is genuinely "private," not even for the director of the world's largest spy agency.

No matter what assumptions, promises or email ploys we might rely on, the one safe approach today is to assume every Internet search, each email, any tweet or Facebook post is at least a discoverable whisper to the world, if not an outright shout.

The implications of that online reality go well beyond personal discomfort or professional disgrace, all the way to First Amendment principles underpinning free speech, free press, petition and the right to associate freely.

Anonymous speech and freely associating with others clearly enhance our ability to seek change in government policies without the chilling impact of "Big Brother" taking names -- and, at least potentially, punishing citizens.

We have only to look at the start of the nation to see the value the Founders placed on anonymity. Alexander Hamilton, John Jay and James Madison used the pen name "Publius" in circulating the 85 essays and articles of the Federalist Papers in 1777 and 1778, discussing what became the principles of the U.S. Constitution.

More than a century later, the core value of individual privacy was declared in an 1890 law review article, "Right to Privacy," co-written by Louis Brandeis, later a renowned Supreme Court justice. Noting that "recent inventions and business methods" were fueling an unprecedented increase in gossip and that "to satisfy a prurient taste the details of sexual relations are spread broadcast in the columns of daily papers," the article called for legal protection of the right "to be let alone."

In 1958, the U.S. Supreme Court tied privacy directly to the right of groups not to disclose the names on their membership lists. In NAACP v. Alabama, the Court specifically supported the idea that such groups could shield their members from potential reprisals.

But fast-forward to 2011, when the Supreme Court ruled in favor of requiring Washington state to disclose the names of those who signed petitions to overturn a gay-marriage law. The signers' fear of being targeted was an acknowledged part of the legal debate. So much for anonymous speech in that one.

The tools of privacy from years past seem as inefficient as they do quaint in today's era of electronic transparency. Where once lowering the window shades, closing an office door, or sealing a letter for the mail might suffice, a tsunami of data-mining from online official records, and the global, instantaneous and apparently eternal cache of Facebook photos, tweets and email trails, makes closing the e-door or sealing an archive all but impossible.

Under the 1986 Electronic Communications Privacy Act, federal prosecutors can simply issue a subpoena to get emails and such more than six months old.

A recent Associated Press report said that's usually enough to get Internet companies "to reveal names and any other information that they have that would identify the owner of a particular email account."

The AP story said a Google report showed it "complied with more than 90 percent of the nearly 12,300 requests it received in 2011 from the U.S. government for data about its users."

In the Petraeus matter, the FBI was able to track strings of emails with his ex-mistress -- and in a related search, obtain what some reports call "30,000 pages" of emails between another general and a second woman linked to the scandal, all in a matter of weeks or months.

For those of us tempted not to worry about privacy because we "haven't done anything wrong," there's a non-criminal Pandora's box to stress about: aggregation of private information.

This includes everything from our use of supermarket discount cards and online health information to lists of videos we rent and websites we visit -- all maintained by someone, somewhere, available to others and all of it largely without our knowledge.

Be that as it may, the First Amendment's role is to forestall government intrusion and abuse -- so that we may write and speak freely, and gather with others of like minds, perhaps to seek a change in direction by our government.

We cannot be distracted by the tawdry details of infidelity involving a few people from seeing yet another signal that all our lives are more open than ever to agents of government.

Gene Policinski is senior vice president and executive director of the Nashville, Tenn.-based First Amendment Center. gpolicinski@fac.org