Having had another look at the image, I'm not so sure now. Is there a Facebook logo anywhere else on the page that identifies it as coming from them? Could this just be somebody phishing?
Either way, I'd have a look at what you're posting and delete anything you think they don't like, just to be sure. Is there anything on there that could be regarded as racist, homophobic, sexist etc?
If you check the web address, if I'm reading it right, then you're actually contravening the Site Rules of photobucket - not facebook, all that may happen will be your photobucket account will have a user violation message posted on your account. By ignoring it the site administrators may delete your account for site violation.
I think the OPer will know whether they saw this while logged in to Facebook or Photobucket.
I guess that, while in Facebook, they saw this, took a screen-shot and are using Photobucket to show us what they saw.
Have you uploaded a video or slide show that has a music track on it? It could be the music content that is copyrighted, a friend of mine did this and that was the message he received, the slide show was not then available either. Just acknowledge the message and all will be fine.