A developer that's trying to highlight the dangers of forgetting about personal privacy has unveiled a new service that shows how easy it is for users to have their phone numbers acquired by Facebook visitors.

The service, called Evil, sifts through Facebook groups to find posts left by users that include their phone numbers. It then displays the person's name and all but the last three digits of their phone numbers on the site.

The issue, according to Tom Scott, the tool's creator, is that there are a slew of Facebook groups that are created each day by folks who lose their phones and need their friends' numbers back. Rather than e-mail each person individually, those people create groups where users can simply post their numbers to the group's wall. From there, the group owner can take the numbers and put them into their new phone.

It's a simple, useful process for the group owner. But what those who are adding their numbers to the wall might not realize is that the majority of those groups are set to "public." And, according to Scott, a public group is viewable by anyone anywhere in the world, regardless of whether they're a Facebook user or not.

Scott's Evil app aims to highlight that flaw and scare people into thinking twice before sharing content on Facebook. He also tells them that they should remove their phone numbers from any groups they might have shared them with. If they don't, the numbers are readily available with a simple Google search or by sifting through groups.

Evil might not make affected users or Facebook itself very happy, but it effectively highlights a key issue with the social network: Users are too willing to share information. And, so far, they don't appreciate the fact that by sharing sensitive information, it could potentially be viewed by folks across the Web.

Facebook is dealing with privacy and security issues of its own that it needs to address. But the social network can't be fully secure until users start taking responsibility for their own privacy. It's important for users to remember that.

-- Don Reisinger

twitter.com/donreisinger