The advent of social media has had everyone throwing words around such as transparency, interaction and sharing. But the hoopla this week over Facebook’s Beacon suggests that the world is not as transparent and willing to share personal information as many business executives had hoped. Apparently the extent of how “social” consumers are willing to be is still a mystery to the business world.

In case you’ve been living under a rock, Facebook announced Social Ads earlier this month, as well as the launch of Beacon, “a new way to socially distribute information on Facebook.” Beacon is “a core element of the Facebook Ads system for connecting businesses with users and targeting advertising to the audiences they want.”

With public outcry and petitions galore from Facebook users, the company has backed down a little and is now offering users the option to publish or not publish the information in the “stories” feed. It seems that all the social media fans are not willing to be quite so transparent as having their online shopping behavior become news to their “friends.” (Shocker!)

A universal opt-out has been unclear to-date, although Charlene Li of Forrester Research just published official word from Facebook that “Adding Beacon-generated stories will require an explicit opt-in by the member. Before, if the member did nothing, the story would appear.”

There’s always a catch to free services, friends – Facebook has just taken the online advertising model a bit too far. Duncan Riley of TechCrunch does a good job here of dissecting exactly what this means to users. We haven’t canceled our Facebook accounts – yet – have you?