A couple of days ago my friend Chris Allbritton — the excellent blogger of Back To Iraq who has been working in Time’s Baghdad bureau — wrote about John Martinkus, an Australian journalist friend of his who was kidnapped then released. Martinkus said that during the interrogation, the captors vanished briefly to check up on the journalist’s work; Chris suspected that they Googled him.

Apparently that’s precisely what happened, according to Martinkus’ employers, SBS. As Australia’s National Nine News reports:

“They Googled him, they checked him out on a popular search engine and got onto his own website or his publisher’s website and saw he was a writer and journalist,” Mr Carey told AAP.

This is a really intriguing moment for the reputation economy. More and more, this is one of Google’s central functions: A way to quickly verify someone’s reputation. Two years ago, I blogged about what I called the “untouchables” — people who do not show up on Google at all. And increasingly I find that when I do a search for someone on Google and can’t find anything about them — not a single page — I’m quite freaked out. It’s like running into some “lost man” from a 1960s cold-war spy novel, somebody who has deliberately adopted a new identity and erased all tracks of themselves. Not being visible on Google now seems kind of antisocial: In a digital age, it’s simply not polite.

Interestingly, Collision Detection has become a really powerful reputation-management device for me. Almost every time I call a company to interview a CEO, the company’s public-relations person immediately googles me, finds this blog, and reads a whole bunch of entries; then they’ll mention it to me when we talk, as if to tell me see, I know something about you.

In a recent edition of New York magazine, the staff presented readers with a short guide on “how to disappear”. Among the first suggestions?

Begin your new life of anonymity by filing an action with the New York Lower Civil Court to change your name to Michael or Emily—the most common newborn names in the city—and then pick a Googleproof surname like Smith.

(Thanks to Jason Uechi for this one!)