Summary version:

When you share an image, you relay your information back to the originator, and potentially expose your friends list to them.  Don’t share images from sources you don’t know.

Longer version:

Okay, we’ve all seen these:

Awww…  That’s so sweet.  I do that thing/feel that way/agree with that sentiment, so I’ll share that to my wall, so everybody knows I do that thing/feel that way/agree with that sentiment.

Well, unfortunately, dear reader, there’s a dark side.  When you share a post, the original poster is alerted to that fact.  So what, you ask?  Well, that alerts the poster to your existence, and, if you haven’t protected your profile (see my last two notes), you may expose your friends’ list to them.  Again, so what?  Well, here’s where it gets fun.  You share an image, five of your friends share the image, five of their friends share the image, and so on.  After six generations of this, information about more than 97,000 people has been relayed back to the original poster.  This information is easily harvested by a program running on the original poster’s computer.  Once that information has been harvested, it sets to downloading the friends list of as many of those users as it can.  Next, it goes after their friends lists, and so on.

Following the steps in the second note, is a good way to protect yourself from this kind of “bot spidering,” but there’s more you can do.

The easiest way to protect yourself from being part of the harvesting tree, is to only share images that were originally posted by people you know.  By that, I mean that, above the image, it says that the person shared a photo, as opposed to “person shared other person’sphoto”.

That said, if you absolutely must post the picture of the puppy, words, or whatever, you might consider downloading it, and then re-uploading it.  That creates a break in the chain, as Facebook sees your uploaded image as being separate from the original.

Or, if it’s a picture of text, and you believe in it enough to share it with others, then type it as your status message.  If nothing else, it shows that your opinion of it matters more than a click that’s just going to clutter up others’ newsfeeds.

Be safe out there!

Further reading:

• http://www.pcworld.com/article/243014/facebook_easily_infiltrated_by_dataharvesting_bots_researchers_find.html
• http://www.publicserviceeurope.com/article/3278/the-problem-with-facebook-likes-and-data-harvesting
• http://www.face-to-facebook.net/theory.php