It seems  the wife of Sir John Sawers, next in line to run England’s super-secret spy agency MI6, had been using Facebook to share pictures of her husband and family and post updates on their whereabouts – not the kind of behavior covert operatives normally go in for.

As you can imagine, the British tabloids are having a field day, though as one British government official put it, how important to national security can it be to know Sawer wears Speedos.

But the incident points up the potential trouble of using social networks.

Facebook, Twitter and LinkedIn have gone out of their way to make it easy to update your status, so the world can know “What are you doing now?”

That’s a great way to keep colleagues and potential business partners apprised of your blog posts, projects, business ventures, convention stops or speaking engagements. But it’s also easy to end up mixing your business life with your personal life. In fact, social media gurus encourage you to devote a small portion of what you share on Twitter or blogs to real-life stuff, the better to make you sound human, not just a robo-pitchman for whatever it is you do or sell.

But as Mrs. Sawers found out, mixing things up can lead to trouble. So can providing so much about your business life you end up sharing details better left unsaid.

Major news media outlets have begun addressing this issue by crafting social media policies that, among other things, spell out what their writers can and can’t do on social networks like Twitter and Facebook. The Wall Street Journal published guidelines in May with requirements that, among other things, reporters should avoid discussing articles before they’re published, meetings they’ve attended and “friending” potentially confidential sources.

Freelance writers aren’t normally beholden to a client’s social media usage requirments – unless they’re written into a contract, which is something I have yet to see.

So it’s up to you to decide what you should and shouldn’t share. Some suggestions:

* Don’t share specifics of an assignment. Crowdsourcing has become a popular for finding story sources, but there’s a way to share the general nature of what you’ll be writing about without giving everything away. When in doubt, err on the side of caution.

* Remember everything you say online could be there forever. In the heat of the moment you may feel like sharing the ugly details of an assignment gone wrong, names and all. But in an industry where editors and writers move around almost monthly, so much openness can come back to haunt you. If you simply must vent, call a trusted friend, or use the writers’ message board you subscribe to, but consider not actually naming names.

* Use some social networks for work and some for fun. Some writers use Twitter and LinkedIn for work and Facebook for fun, so they can shield all of the personal stuff they share about their families, vacations and leisure activities from the potentially prying eyes of editors, readers and other nosy types. If this is how you want to roll, use the appropriate Facebook settings to keep your info private, and don’t feel bad about saying “No thanks” when business associates ask to connect with you there and redirect them to the networks you use for business.

If you’re on social networks, how do you keep your business and private lives separated?