The following, slightly adapted, was my introduction of Christine Rosenthis morning when she gave one in this year’s series of the John Henry Cardinal Newman Lecturesof the Institute for the Psychological Sciences at the offices of the Family Research Council in Washington. Look for a video of the lecture itself, titled "Virtual Friendship and the New Narcissism" to be posted, in due course, here.

The night before last, at or about four o'clock in the morning Pacific Time, an intruder walked into the San Francisco apartment of Dave Prager, a technology writer and Internet TV commentator for the station Revision3. Dave’s first thought was not to call the police or to confront the man who had gone into his bathroom but to go on-line and describe what was happening on Twitter. Not too surprisingly, the consensus of the "tweets" he received in return, even at this hour of the morning, from his Twitter-sphere was that he should either call the police or confront the man. He decided to do the latter. But not before he turned on his webcam.

If you want to see what happened, you can look it up on YouTube, where about ten minutes of video shows our Twittering hero talking — not twittering — to a drunk. The drunk has by this time taken his trousers off and collapsed into the recently vacated bed of Mr Prager, who tells his unwelcome visitor that he has to get up, that his actions are "insane" and that, significantly, "I don’t even know who you are." Of course, he doesn’t know who all the people reading his tweets on Twitter or watching him on YouTube try to drag a drunk from his bed at four in the morning are either. But these unknown people, in whom he has chosen to confide his deepest thoughts at this moment of anxiety and fear, have at least had the good manners to stay in the etherial electronic world where they belong instead of wandering into his apartment like the "random dude," as he calls him, now in his bed.

"Isn’t this a little weird for you?" Mr Prager asks the sleeping drunk. "Maybe it’s normal for you. It isn’t normal for me." And then he tells him, "You’re on the internet, dude" — which presumably is just the opposite: normal for him, weird for the drunk. Not that the drunk seems to know or care anything about it, one way or the other. Yet the random dude and his equally random if unwilling host are now linked together on YouTube forever — or until the Internet dies, whichever comes first — together with Mr Prager’s video diary of the event, in which he tells us, on finally expelling the intruder, how he felt about it all.

Here’s some of what he said:

The story right now is that he says, "I’m just trying to follow excuse me." Dude’s messed up. I’m kind of embarrassed of my language, by saying, "Dude, like what’s your deal, man?" But I figure that’s just the easiest way to just, uh, say a few things from a generalistic term. So. . . .I might keep this up for a little bit and see what happens. . . .I think my attitude about it is way too humorous, but um, maybe I take comfort in the fact that I can share it with a few people — makes it a little easier. I don’t know what else to say. So, um, I guess I’m off right now. Maybe update Twitter with a couple details, in case anyone happens to be interested. And if you are interested, I guess I’m flattered.

Like Mr Prager himself, I don’t know what else to say. But I know someone who does. Christine Rosen has spent more time thinking about electronic intrusions into our lives, both welcome and unwelcome, as well as the moral and psychological consequences of electronic intimacy and the boundaries of the self in the information age, than anyone I know of. As my colleague and the Fellow for the Project on Biotechnology and American Democracy at the Ethics and Public Policy Center, she has published many of her findings in our journal, The New Atlantis, of which she is also a Senior Editor, and so done as much as anyone to put it and us on the intellectual map. She also has, as she says, "a sort of built-in laboratory at home," since she has twin two-and-a-half-year-old boys who are quite outspoken in their disapproval if she allows herself to become distracted by technology.

Though still appallingly young, she has published several books including, most recently, My Fundamentalist Education which was chosen by The Washington Post as one of the best non-fiction books of 2006. Her writings have also appeared in The New York Times Magazine, The Wall Street Journal, The Washington Post, The New Republic, The Weekly Standard, The New England Journal of Medicine and many other publications, and her appearances on television shows — and, now, even Internet TV — are too numerous to mention. But her words, which we are about to hear on the subject of "Virtual Friendship and the New Narcissism," are unlike the "tweets" of Mr Prager at least in this respect: that we are the ones who are flattered to hear them.