If you have any significant number of friends on Facebook, you’re treated every year to a virtual swarm of well-wishers descending on your profile to post birthday salutations. We revel, if only briefly, in this shower of attention. It subconsciously reaffirms the significance, or at least the distinctiveness, of our own existence.

It’s always somewhat amusing to see the popular media gush about “social networking sites such as Facebook and Myspace.” Both are always mentioned in a single breath as the next big thing for 20-somethings.

To these, I would also add Steam, a video-game-download client that also has a nicely-integrated “friends” feature, and Twitter, which consists entirely of brief-text posts.

The original theory behind social networking was solid: You would look up people you knew in real life, add them to a list and use the site as a supplement to actually interacting with them.

That sounds a bit quaint, doesn’t it? It may well be that these sites are dumbing down social bonds rather than strengthening them.

Do you have old friends you haven’t seen in while? Add them, write two lines on their wall and forget about catching up over lunch. Social networking has become all about the present; with few exceptions, there’s no time or space for long-term plans or old memories.

Then there are the random friends, the people you’ve never met. The existence of the “random add” subverts the entire paradigm of social networking.

Myspace, with its profusion of band and porn star profiles, is probably the biggest offender in this regard, but Facebook has them too. Yuppies, total losers and gorgeous blondes with a thousand tagged photos. On the Internet, you can have it all.

I too, am subversive, linked into a network of delightful, but essentially unknowable people I’ve never met. Within limits, the vice is a nice diversion.

What is disturbing, though, is that many people view it as a social circle, as if one could ever count on random “friends” for anything in tough times.

Finally, there is the abridgement of the social networking medium itself ­— its transformation into an extended series of brief, mostly unfunny one-liners, particularly on Twitter and, recently, Facebook.

Someone in your news feed has a lot of homework. He also has been drinking. He’s endorsing political candidates using a copy-and-paste message. He’s a vampire or a mafia don in some application. He won’t stop spamming you with unwanted invites. And you can’t de-friend him because that’s the equivalent of socking him in the face with brass knuckles on.

Of course, not much of this would ever make for interesting conversation, but it suffices for “shares” or “tweets.” They are the self-absorbed detritus of human existence — the id unleashed at the altar to the mundane. Somehow, despite the thinness of this online blather, we often accept “shares” and their comments as a substitute for real interaction.

Social networking is like alcohol: Enjoyed with friends in moderation, it’s a great thing. Whatever my reservations about the social networking revolution, I still react to the words “I don’t have Facebook” the same way I might react to the words “I have the plague.”

If abused, however, social networking sites become a false existence. Never, ever forget that the Internet is a poor substitute for personal contact.

Reach columnist Russ Wung at opinion@dailyuw.com.