Spend time in a social networking space, and you’re liable to say something very personal. The intimacy of the environment, full of appealing color schemes and friendly green buttons, can make you feel as if you’re in your own living room, surrounded only by the people you feel safest with.

But you’re not. You’re online and you’re letting your hair down in public.

Of course, every little thing you tweet, twine, ‘tube ‘Space, ‘book, or flick’ may not reveal that much about you. All the same, little clues do add up — whether you’re a networker, blog-follower, group-joiner, poll-taker or credit-card user. And that should make you stop and think. While the engines of social media are very, very good at protecting you, the same may not be true of your friend’s-friend’s-friend’s-friend — the person you added to your network in a blur of finger-tapping one snowy night in December.

In light of that, do you really want to share that you’re out of your apartment, on vacation? That’s your apartment: “on the Upper West Side,” next to “that Starbucks in the old bank building,” on “a low floor” from which you saw “a dude doing handstands on his skateboard” — whose photo you posted on Snapfish.

In fact, now that it’s so easy to open up about ourselves online, you have to wonder whether this non-stop-information-sharing is turning our lives into a reality show. And when you figure that “Big Brother” has a Facebook page, it’s clear that the merging of media and life has entered a dizzying vortex of tangled cross-references.

So maybe it’s time we developed a set of advisories to help people protect their privacy in digital space. After all, for millions of people, social networking is no longer something they use objectively, like a hammer. Their online presence is part of their identity, to the point of becoming a sixth sense.

As such, this new sense needs to be protected, just a surely as we shield our eyes from direct sunlight — or from an episode of “Fantasy Island.” For it’s only on that island that we can afford to share life’s secrets unrestrainedly with mysterious strangers — and expect to have a positive outcome.

Ultimately, however, protecting your privacy online may depend more on being self-aware than on rules and regulations. Before each post, you might want to ask yourself:

     • Does this content reveal more about my location, occupation, health
        or other vital statistics than I’m ready to share with the entire planet?

     • Could it, in any context, lead someone to question my respect for other people?

     • Is it a POV I’m sure I want to be associated with, for as long as electrons
       continue to spin?

And if your inner children ask, “What about spontaneity?” sit them down with some milk and cookies and say, “Share as much as you like, my darlings — just make sure you use your Digital Voice.”