(Note: there is a discussion of this post on Hacker News.)

I posted some time back that one drawback of the "cloud" is that you can't control how data you post to a "cloud" service is used. Facebook has now provided us with an even better example than the case (Instagram) I talked about in that post.

According to groovyPost (via Hacker News), Facebook uses data in your contact list to create "shadow" accounts for people who aren't even on Facebook. It isn't clear exactly how Facebook uses the data in these "shadow" accounts, but their previous behavior does not inspire confidence. There is no way for the user to turn off or control this behavior; it's not even visible to you as a Facebook user. In fact, based on a quote from a Facebook representative given in the article, Facebook apparently believes that allowing users to control this behavior would violate Facebook's freedom of speech!

(I should make clear that if you only sign in to Facebook through the Facebook website, as far as I can tell, it doesn't access any of your contacts. But if you sign in to any other site and connect that account with your Facebook account--for example, if you use the Gmail feature that lets you automatically log in to Facebook using your Gmail account--then any contacts you have on the other site will get harvested by Facebook. Or, if you use Facebook's smartphone app, all of your contacts stored on the phone will get harvested.)

I don't want to draw out this post with a discussion of whether corporations even have freedom of speech the way individuals do (that's a whole other can of worms). My point here is simply that it's one thing to decide that you don't mind your own personal information being spread all over the Internet. I've said before that I personally don't choose to do that, but as long as it's just your own information, it's your choice. But Facebook has decided to put you, if you're a Facebook user, in a position where you might be compromising other people's personal information, even if they would much rather you didn't, and without giving you any choice in the matter. If that isn't something you want to do, you should think carefully about how you use Facebook.