I first wrote this post on my public Facebook page in May of 2010 as a response to friend requests from readers, publicists and other people whom I hadn’t actually met. Since then, things have changed: Facebook’s privacy implications have gotten trickier, Plaxo and MySpace vanished from relevance, LinkedIn is more useful, a follower-etiquette question has come up on Twitter, and Google+ has brought its own social-networking issues.

So here’s an update on what leads me to accept a friend request, decline it, or passive-aggressively pretend I never saw it.

Facebook: Last year, my rule was that we had to have met and communicated, even if only by phone or e-mail, before I’d accept your friend request. But as Facebook’s constant tinkering increases the default exposure on each account–and as features like the upcoming timeline interface make it easier to mine friends’ histories for dirt–the liability of an ill-chosen Facebook connection has increased.

Meanwhile, the increasing noisiness of Facebook’s site has reduced the marginal value of each new friend in the News Feed. So I’m pickier about friend requests and have unfriended people with whom I only had one good chat and then never heard from on the site. (Go ahead and unfriend me if you wish. I don’t take offense if people disregard my own Facebook entreaties: It remains an optional service, notwithstanding what its management might say.)

I have yet to enable Facebook’s new subscription option, even though it’s intended for people like me with some level of public identity. My Facebook page already has a large, growing audience, so unless I were to fold that venture back into my profile I’d have yet another online outlet to fill with witty morsels.

Google+: I like how Google’s latest venture into social networking doesn’t require reciprocity–if you want to add me to one of your circles, go right ahead! And because so much of my G+ audience has been defined by my occupational social graph, G+ seems to be evolving as a forum to discuss things I cover. But that doesn’t mean I’ll necessarily “circle you back”… and no, I don’t know I even like that bit of Googlespeak.

Twitter: The same principle applies to Twitter. I follow far fewer people than follow me because I find Twitter works best as a news network, not a sort of friend radio, and I don’t need its signal-to-noise ratio any lower. So if you’re not sharing useful tidbits about technology, journalism or a few other subjects that fascinate me, I’m probably not going to follow you–although I’ll certainly notice your tweet if you mention me in it. But please do follow me anyway!

Foursquare: Seriously, what is it with strangers who want to know when I hit the grocery store? I assure you, I am not that interesting (aside from the gratuitous check-ins I did from the Kennedy Space Center during NASA Tweetups this summer). My rule here hasn’t changed: I have to know where you live or your cell phone number.

I’ve also realized that I don’t need to publicize my Foursquare activity beyond the service to get its primary benefits: useful tips about places I visit, plus the occasional discount and the cheap thrill of claiming a mayorship. So I disconnected my Twitter account; I may link my Facebook account, since that has some privacy limits while my Twitter presence has none.

LinkedIn: Shockingly enough, leaving my job at the Post led me to put serious time into my LinkedIn page. (Better yet, I’ve since received substantive business inquiries through the site, one of which has already put money in my bank account.) I remain fairly liberal in my acceptance of LI invitations, but I still appreciate knowing where they’re coming from–for instance, because we’ve met before or you work in a related field. In other words, please spend 30 seconds to write something more personal in your request than the default ”I’d like to add you to my professional network on LinkedIn.” You all do know that’s text you can edit before sending the request–right?

Now that I’ve exposed my social-media snobbery, how do you make these decisions?