• Low-tech is very effective. Movie-plot threats -- terrorists with crop dusters, terrorists with biological agents, terrorists targeting our water supplies -- might be what people worry about, but a bunch of trained (we don't really know yet what sort of training they had, but it's clear that they had some) men with guns and grenades is all they needed.

• At the same time, the attacks were surprisingly ineffective. I can't find exact numbers, but it seems there were about 18 terrorists. The latest toll is 195 dead, 235 wounded. That's 11 dead, 13 wounded, per terrorist. As horrible as the reality is, that's much less than you might have thought if you imagined the movie in your head. Reality is different from the movies.

• Even so, terrorism is rare. If a bunch of men with guns and grenades is all they really need, then why isn't this sort of terrorism more common? Why not in the U.S., where it's easy to get hold of weapons? It's because terrorism is very, very rare.

• Specific countermeasures don't help against these attacks. None of the high-priced countermeasures that defend against specific tactics and specific targets made, or would have made, any difference: photo ID checks, confiscating liquids at airports, fingerprinting foreigners at the border, bag screening on public transportation, anything. Evenmetal detectors and threat warnings didn't do any good:

  "If I look at what we had, which all of us complained about, it could not have stopped what took place," he told CNN. "It's ironic that we did have such a warning, and we did have some measures."

  He said people were told to park away from the entrance and had to go through a metal detector. But he said the attackers came through a back entrance.

  "They knew what they were doing, and they did not go through the front. All of our arrangements are in the front," he said.

If there's any lesson in these attacks, it's not to focus too much on the specifics of the attacks. Of course, that's not the way we're programmed to think. We respond to stories and not analysis. I don't mean to be sympathetic; this tendency is human and these deaths are really tragic. But eighteen armed people intent on killing lots of innocents will be able to do just that, and last-line-of-defense countermeasures won't be able to stop them. Intelligence, investigation, and emergency response. We have to find and stop the terrorists before they attack, and deal with the aftermath of the attacks we don't stop. There really is no other way, and I hope that we don't let the tragedy lead us into unwise decisions about how to deal with terrorism.

Geneva Framework: a .NET class library called Microsoft.IdentityModel (basically it's an updated Zermatt)

Geneva Server: This is essentially ADFS v2, built on top of the Geneva Framework

Geneva CardSpace: This is CardSpace v2.

This link takes you to the "Geneva" landing page at Microsoft, where you'll find links to all of the bits, as well as the whitepaper v2. The new version of the whitepaper was co-authored by myself and a PM on the Geneva Framework team, Sesha Mani, who added a bunch of new details based on the PDC version of the framework.

Economists have long understood the corollary concept of Coase's ceiling, a point above which organizations collapse under their own weight -- where hiring someone, however competent, means more work for everyone else than the new hire contributes. Software projects often bump their heads against Coase's ceiling: recall Frederick P. Brooks Jr.'s seminal study, The Mythical Man-Month (Addison-Wesley, 1975), which showed how adding another person onto a project can slow progress and increase errors.

What's new is something consultant and social technologist Clay Shirky calls "Coase's Floor," below which we find projects and activities that aren't worth their organizational costs -- things so esoteric, so frivolous, so nonsensical, or just so thoroughly unimportant that no organization, large or small, would ever bother with them. Things that you shake your head at when you see them and think, "That's ridiculous."

Sounds a lot like the Internet, doesn't it? And that's precisely Shirky's point. His new book, Here Comes Everybody: The Power of Organizing Without Organizations, explores a world where organizational costs are close to zero and where ad hoc, loosely connected groups of unpaid amateurs can create an encyclopedia larger than the Britannica and a computer operating system to challenge Microsoft's.

Shirky teaches at New York University's Interactive Telecommunications Program, but this is no academic book. Sacrificing rigor for readability, Here Comes Everybody is an entertaining as well as informative romp through some of the Internet's signal moments -- the Howard Dean phenomenon, Belarusian protests organized on LiveJournal, the lost cellphone of a woman named Ivanna, Meetup.com, flash mobs, Twitter, and more -- which Shirky uses to illustrate his points.

The book is filled with bits of insight and common sense, explaining why young people take better advantage of social tools, how the Internet affects social change, and how most Internet discourse falls somewhere between dinnertime conversation and publishing.

Shirky notes that "most user-generated content isn't 'content' at all, in the sense of being created for general consumption, any more than a phone call between you and a sibling is 'family-generated content.' Most of what gets created on any given day is just the ordinary stuff of life -- gossip, little updates, thinking out loud -- but now it's done in the same medium as professionally produced material. Unlike professionally produced material, however, Internet content can be organized after the fact."

No one coordinates Flickr's 6 million to 8 million users. Yet Flickr had the first photos from the 2005 London Transport bombings, beating the traditional news media. Why? People with cellphone cameras uploaded their photos to Flickr. They coordinated themselves using tools that Flickr provides. This is the sort of impromptu organization the Internet is ideally suited for. Shirky explains how these moments are harbingers of a future that can self-organize without formal hierarchies.

These nonorganizations allow for contributions from a wider group of people. A newspaper has to pay someone to take photos; it can't be bothered to hire someone to stand around London underground stations waiting for a major event. Similarly, Microsoft has to pay a programmer full time, and Encyclopedia Britannica has to pay someone to write articles. But Flickr can make use of a person with just one photo to contribute, Linux can harness the work of a programmer with little time, and Wikipedia benefits if someone corrects just a single typo. These aggregations of millions of actions that were previously below the Coasean floor have enormous potential.

But a flash mob is still a mob. In a world where the Coasean floor is at ground level, all sorts of organizations appear, including ones you might not like: violent political organizations, hate groups, Holocaust deniers, and so on. (Shirky's discussion of teen anorexia support groups makes for very disturbing reading.) This has considerable implications for security, both online and off.

We never realized how much our security could be attributed to distance and inconvenience -- how difficult it is to recruit, organize, coordinate, and communicate without formal organizations. That inadvertent measure of security is now gone. Bad guys, from hacker groups to terrorist groups, will use the same ad hoc organizational technologies that the rest of us do. And while there has been some success in closing down individual Web pages, discussion groups, and blogs, these are just stopgap measures.

In the end, a virtual community is still a community, and it needs to be treated as such. And just as the best way to keep a neighborhood safe is for a policeman to walk around it, the best way to keep a virtual community safe is to have a virtual police presence.

Crime isn't the only danger; there is also isolation. If people can segregate themselves in ever-increasingly specialized groups, then they're less likely to be exposed to alternative ideas. We see a mild form of this in the current political trend of rival political parties having their own news sources, their own narratives, and their own facts. Increased radicalization is another danger lurking below the Coasean floor.

There's no going back, though. We've all figured out that the Internet makes freedom of speech a much harder right to take away. As Shirky demonstrates, Web 2.0 is having the same effect on freedom of assembly. The consequences of this won't be fully seen for years.

Here Comes Everybody covers some of the same ground as Yochai Benkler's Wealth of Networks. But when I had to explain to one of my corporate attorneys how the Internet has changed the nature of public discourse, Shirky's book is the one I recommended.

This essay previously appeared in IEEE Spectrum.

This reality of the information age might be particularly stark for the president, but it's no less true for all of us. Conversation used to be ephemeral. Whether face-to-face or by phone, we could be reasonably sure that what we said disappeared as soon as we said it. Organized crime bosses worried about phone taps and room bugs, but that was the exception. Privacy was just assumed.

This has changed. We chat in e-mail, over SMS and IM, and on social networking websites like Facebook, MySpace, and LiveJournal. We blog and we Twitter. These conversations -- with friends, lovers, colleagues, members of our cabinet -- are not ephemeral; they leave their own electronic trails.

We know this intellectually, but we haven't truly internalized it. We type on, engrossed in conversation, forgetting we're being recorded and those recordings might come back to haunt us later.

Oliver North learned this, way back in 1987, when messages he thought he had deleted were saved by the White House PROFS system, and then subpoenaed in the Iran-Contra affair. Bill Gates learned this in 1998 when his conversational e-mails were provided to opposing counsel as part of the antitrust litigation discovery process. Mark Foley learned this in 2006 when his instant messages were saved and made public by the underage men he talked to. Paris Hilton learned this in 2005 when her cell phone account was hacked, and Sarah Palin learned it earlier this year when her Yahoo e-mail account was hacked. Someone in George W. Bush's administration learned this, and millions of e-mails went mysteriously and conveniently missing.

Ephemeral conversation is dying.

Cardinal Richelieu famously said, :If one would give me six lines written by the hand of the most honest man, I would find something in them to have him hanged." When all our ephemeral conversations can be saved for later examination, different rules have to apply. Conversation is not the same thing as correspondence. Words uttered in haste over morning coffee, whether spoken in a coffee shop or thumbed on a Blackberry, are not official pronouncements. Discussions in a meeting, whether held in a boardroom or a chat room, are not the same as answers at a press conference. And privacy isn't just about having something to hide; it has enormous value to democracy, liberty, and our basic humanity.

We can't turn back technology; electronic communications are here to stay and even our voice conversations are threatened. But as technology makes our conversations less ephemeral, we need laws to step in and safeguard ephemeral conversation. We need a comprehensive data privacy law, protecting our data and communications regardless of where it is stored or how it is processed. We need laws forcing companies to keep it private and delete it as soon as it is no longer needed. Laws requiring ISPs to store e-mails and other personal communications are exactly what we don't need.

Rules pertaining to government need to be different, because of the power differential. Subjecting the president's communications to eventual public review increases liberty because it reduces the government's power with respect to the people. Subjecting our communications to government review decreases liberty because it reduces our power with respect to the government. The president, as well as other members of government, need some ability to converse ephemerally -- just as they're allowed to have unrecorded meetings and phone calls -- but more of their actions need to be subject to public scrutiny.

But laws can only go so far. Law or no law, when something is made public it's too late. And many of us like having complete records of all our e-mail at our fingertips; it's like our offline brains.

In the end, this is cultural.

The Internet is the greatest generation gap since rock and roll. We're now witnessing one aspect of that generation gap: the younger generation chats digitally, and the older generation treats those chats as written correspondence. Until our CEOs blog, our Congressmen Twitter, and our world leaders send each other LOLcats – until we have a Presidential election where both candidates have a complete history on social networking sites from before they were teenagers– we aren't fully an information age society.

When everyone leaves a public digital trail of their personal thoughts since birth, no one will think twice about it being there. Obama might be on the younger side of the generation gap, but the rules he's operating under were written by the older side. It will take another generation before society's tolerance for digital ephemera changes.

This essay previously appeared on The Wall Street Journal website (not the print newspaper), and is an update of something I wrote previously.