Are you sure?

Just today I've been getting 'Are you sure you want to like this post?' pop-ups when I hit like on a post.
Not consistently, though.
What gives?
Is this going to be a new feature, and if so, where can I disable it, because it's annoying?


Edit: in trying to replicate this, it appears that the pop-up only happens on a post with a youtube link (post your song of the day thread, for example) and now, 10 minutes after creating this post, I can't replicate it at all.

I'm pretty sure I didn't imagine this. Send help.