I lost a friend last week. I know, because, Facebook told me so. It might, in fact, be more accurate to say that Facebook made the decision for me – the decision to conclude a friendship over which I was wringing my hands.

A close friend of mine, you see, had become increasingly distant over many months, coping with issues of his own. As I watched him alienate family members while doing his best also to push me away, his personality evolved. The proverbial “they” say that people don’t change, but of course they do, and I am no less guilty of this than anyone. In this case, however, a person I had known for several years began offering unsolicited criticism and inflicting an ugly, frequently caustic and ever-more-arrogant attitude on the rest of the world – when he was feeling like answering messages at all, which he often wouldn’t.

Then, one day, I logged into Facebook and discovered he had “unfriended” me. While I was grappling with whether I should cut ties with someone I regarded as a brother, in order to remove from my life a negative influence, he was clicking a mouse and rendering me a virtual unperson. For a teenage girl, this would be a mortal offense. For me, as an adult and in perspective against the rest of my life, it was merely an irritant. But it was also a sobering declaration. I realized just how important Facebook has become in facilitating both the development and the termination of real-life friendships. In the synchronicity that often accompanies such mundane revelations, I quickly found other friends and family acting out this very phenomenon.

Surfing through my Facebook friends’ pages, I discovered a relative embroiled in a furious argument with an even more distant relative. The exchange was pretty ugly, if harmless, and revealed a combative side to both individuals I hadn’t realized existed. I vowed to stay out of it.

The same day, I spoke to another friend of mine whose wife, daughter, mother and father are all on Facebook. He’d received a frantic alert in the early morning from his mother, who, through his father, reported that his daughter had been leaving inappropriate comments on the site. It turned out that his dad, new to social networking, had misconstrued comments made by a friend of the daughter’s as her own statements (an easy mistake to make, given how Facebook displays “wall posts” made by friends-of-friends in the user’s activity stream).

Most of these people have in common the fact that they were all, at least at one time, people I would not have thought would have Facebook accounts. The site’s powerful influence on society is thanks to how many people use it, after all. It encourages users to register real names rather than pseudonyms, making it easier to find and connect with your real-life acquaintances (although my friend Sidney Remington, last name withheld, was initially told by Facebook that his name could not possibly be real). Facebook blurs the lines dividing social categories, making virtual strangers “friends” and allowing everyone from your boss to your mother to the members of your high-school graduating class to know what you had for dinner last week (and whether you uploaded a photo of it from your mobile phone).

Facebook has even been given the Hollywood treatment. “The Social Network,” starring Justin Timberlake and Jesse Eisenberg, dramatizes the creation of the site, casting the social network’s pivotal figures as would-be Internet conquerors so polarizing that some speculate whether the film could harm Facebook’s business. The fact that the site is a business is readily forgotten by most of its users, myself included. While Facebook’s revenue streams range from overt banner ads to virtual stores to more subtle, insidious pay-to-play addictive online games, most of its denizens pay no money (directly, anyway) to use it. They take it for granted, and, as they come to rely on it, it insinuates itself into the fabric of their day-to-day lives.

Facebook’s influence has seeped into popular culture so pervasively that it figures regularly in both local and national news. In Cicero, New York, 400 students – roughly 20 percent of the student body – stayed home from school when rumors concerning threats of a Columbine-like massacre were spread using Facebook and text messages. In Lumberton, Pa., this week, an angry female friend actually punched a pregnant woman in a curbside brawl that resulted in injuries to both participants. The cause? Nasty comments made on Facebook a month previously. In Illinois, insults on Facebook have allegedly ended in a brutal multiple stabbing, leaving one woman in the hospital.

Facebook recently pulled “pages linked to a pro-pedophilia advocacy group,” purging the site of links to the North American Man/Boy Love Association (the members of which should, in my opinion, be rounded up by law enforcement regardless of all other considerations, to be confined in concentration camps for the rest of their natural lives). Less horribly, Dunkin’ Donuts is using Facebook to promote its contest to find its No. 1 fan. The Harrisburg University of Science and Technology, for its part, has conducted a relatively unscientific experiment hoping to determine whether its students are addicted to social media. Meanwhile, Glorious Leader Obama, who never met a private citizen or news agency he could not vilify for daring to disagree with him, has set his Orwellian sights on Facebook posters (as well as Skype and Blackberry users) so that he and his thought police can wiretap these services on command.

Social networking has inarguably expanded the “public square.” It has made our personal relationships easier – to initiate, to maintain and to conclude – thanks to the immediacy of online contact regardless of physical distance. It has therefore made our personal lives more volatile. This volatility is neither good nor bad; it is simply a fact of social networking in general and of Facebook in particular.

This is true whether you like it – or whether you, uh, don’t click the “like” button.

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