Warning: This is very much a preliminary post, based on my current understanding of Facebook’s new “LIKE” buttons. But since the feature is live now, I feel like I need to warn people about the ‘potential’ issues sooner rather than later.

So without further ado.

We used to see Share on Facebook buttons on various sites. These were pretty straightforward. You’d click them and it’d stick a link on your Facebook “Wall” so your friends could see that you liked that link and potentially follow it.

Now we have the Facebook Like button. On the surface, it does the same thing. But behind the scenes it’s doing more. It sends not only the link to your wall, but certain meta data that the content producer has tagged the page with. You can, of course, view the source of the page and see what this meta data is, but many people won’t think to do that.

Let me give an example of why this could be problematic. Say you love Guild Wars, but you always play it alone or with one particular friend. You don’t think of it as an MMO, and you don’t like MMOs. In fact you hate WOW and EQ2 and LOTRO and all the other MMOs. They just aren’t your thing.

But Guild Wars you love, so you’re on a page about Guild Wars and you click the LIKE button.

But the site owner considers Guild Wars an MMO, and there’s meta data tagging this page as ‘MMO’ so when you click that LIKE button, you’re telling Facebook that you like Guild Wars and that you like MMOs. That data goes into your account.

The next week you go over to Steam to see what good deals there are. Steam queries Facebook and sees that, according to the data stored with your account, you like MMOs. So it shows you all the great sales on MMOs, and doesn’t show you the sales on single player RPGs, which is exactly what you’re in the mood to buy.

Facebook has misrepresented you. Or rather, you’ve misrepresented yourself because you don’t agree with the meta data on a site you clicked a LIKE button on.

Clearly this example is pretty trivial. But there are other situations where it could matter more. Worse, meta data could be set up to be deliberately misleading. There’s the potential for some pretty ugly shenanigans going on behind the scenes. Think of a political candidate’s page that’s been tampered with so that it has meta data saying you like the opposing party.

If this Like business takes off and lots of sites start polling your Facebook data, this could become a problem.

So I urge you, until we learn more about this system, to avoid using any “Like” buttons you encounter. Maybe Facebook has checks in place to prevent bad things from happening, but maybe not. And it still isn’t clear to me who can, and can’t, query the data associated with your account.

BTW, I put a LIKE button on Dragonchasers last night to see how it worked. I just want to be clear that I put no meta-data behind it, and I thank the folks who helped me test it.

And one last time, this is my understanding of the system as of right now. I could have some or all of this wrong. But just in case I’m right, I wanted to get people thinking about these issues.

I wrote more generally about Facebook’s new features at ITWorld this morning. You might find that post interesting as well.