Senate Intelligence Committee Chairman Mark Warner on Sunday said the leak of classified U.S. military and intelligence documents -- allegedly by a Massachusetts Air National Guardsman working in IT -- wasn't completely unexpected but underscored how the process for secret-keeping needs to be reformed.

"This is a problem that we shouldn't be totally surprised at," Warner, D-Va., told ABC "This Week" co-anchor Martha Raddatz.

"We've known this has been a problem. We actually have to have, I believe, Congress intervene," he went on to say.

Warner said there were multiple issues, including the over-classification of documents; the lack of a single authority overseeing the system who could enforce uniform regulations; and the ability of too many people with clearances to access entire documents -- unnecessarily.

"I believe we need somebody fully in charge of the classification process. And I believe for those most-classified documents, there ought to be a smaller universe [of access]," he said, while urging "continuous vetting" of those with clearances.

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