Well, I would be against it being mandatory with the state of law as it is, because there are examples where you have -- it could be a vulnerable source who would be put under pressure by the person you're putting it to, or somebody may try and discover who your source is. Somebody may go to court and injunct on a matter -- I'm not talking about private lives; I'm talking about matters of high public interest. People may suppress the documents that you have. You're often torn between a circumstance in which you want to keep documents because you may need them if you're sued for libel, but on the other hand, if you're going to be whipped into court pre-publication by somebody who is trying to get the documents back or to discover the source of the documents, you may want to destroy them.
So there are all kinds of dilemmas pre-publication, and I think having a rigid rule that said, "In all circumstances, you must go to the person that you're about to write about" would be difficult as the law stands.