Have you ever been walking down the street with a friend, talking loudly about an amusing personal story and then right as you got to the juiciest part you passed by a stranger on the street who happened to hear the whole thing? You probably didn’t think much of it since you didn’t know the person. But, what if later that day you went to a job interview and that same stranger who overheard your juicy conversation ended up interviewing you for the position? Talk about an embarrassing situation!

While this situation seems highly unlikely in a person’s day to day routine, this happens to people every day on the Internet. Juicy gossip and embarrassing stories about you, your friends and your family can get spread publicly across social media forums, profiles and message boards in plain view of employers, bosses, co-workers and other professionals. Ever wonder if the information you publicly posted about yourself might have cost you a new job or promotion?

There are no passing conversations on the Internet. Anything publicly posted about you will stay online, often in posterity for all of time – that’s why protecting your private information online is so important.

Some web users are under the misconception that the Internet offers the same privacy and protection as the “real world,” when in fact there are very few laws regulating one’s rights to online privacy. A recent article from the Japan Times by Bruce Schneier called, “Offhand but on Record” covers the top privacy concerns with today’s popular social media websites and the advertising partners that support them. Schneier calls for “comprehensive data privacy laws, protecting our data and communications regardless of where it is stored or how it is processed,” but stricter laws alone will not save users who continue to publicly post sensitive information.

Privacy education is the key. If you are going to use social media websites and blogging tools like Facebook, Twitter or WordPress, be aware of the content you publicly post and make sure you set your privacy settings to block sensitive information from public view. When using job boards and career networking websites like Jobdango or LinkedIn, make sure that your resume and profile are up-to-date and don’t contain errors, typos, or other information that could disqualify you from your future job or promotion.

There is a useful article on the, “10 Privacy Settings Every Facebook User Should Know” that can provide social media users with additional tips to protect their privacy online while still utilizing social media websites.

As Internet technologies continue to expand the mining and sharing of information, online privacy will continue to be a growing concern. The best way to maintain your privacy online is to use social media and networking sites with caution and to spread the word about privacy concerns with other professionals online.

About twenty years ago a data service – I forget which one – offered a set of compact disks for sale. It contained the names, phone numbers, addresses and demographic data for everyone in the United States. The product launch was drowned out by the howls of outrage from journalists and Congress. It was an unthinkable violation of privacy. It was Orwellian. The venture sank without a trace. For a while.

Ten years later David Brin wrote The Transparent Society making the case that secrets would soon be impossible to keep and that we shouldn’t even try. The Information Age would usher in an era where everyone’s life was on display. Governments would be models of transparency and openness. Corporations would throw open their records or pay through the nose for the privilege of keeping a few vital things confidential for a limited time. Privacy would be an outdated concept. A decade down the line he seems to be batting .500. While business and government have an increasingly broad view of what they can hide from the public the lives of the Little People are on display to an extent that would have been unthinkable just a few decades ago.

Today? Ah, today is not at all like yesterday. We take it for granted that a few minutes or a few seconds plus a few dollars can extract anyone’s picture, phone numbers and address not to mention the most personal details of his or her life. People sign up for services which tell everyone in the world exactly where they are at all times. Friends of mine with Military Intelligence backgrounds describe how they used to agonize over photos in wallets, matchbooks and brands of cologne to try and piece together the outlines of a target’s contacts and associations. Today their subjects spend hours doing the work themselves with Facebook. Targeted advertising works so well that it’s killing traditional venues like printed newspapers. Twitter and Hotmail are free for the user because they are worth serious money to the real customers – advertisers.

In the last day or so I came across two very interesting takes on how much the world has changed. The BBC’s World Have Your Say featured a spirited worldwide discussion, also available as a downloadable podcast on how transparent our lives should be. My favorite security expert, the brilliant and very readable Bruce Schneier, wrote an excellent piece in the Japan Times. When you exchange information online it stays. Most data you think are private are only that way until someone else decides it’s worth something to share or sell them.

It’s not something most of us think about. We use credit cards. We tweet about whatever comes into our head and broadcast it. But it is very serious business which can have profound repercussions years later. The information we put out for the world to see is worth money to others. We should think about whether it’s worth something to us, how much we should value what we currently give away for free.