"...some reporters figured out that they could use the metadata and remove teh blacked out parts..."
Oh please. It's much simpler than that.
o In Acrobat Reader (or, on a Mac, in Preview), use the text tool to select the text of interest... including the "redacted" sections.
o Copy.
o Paste into MS Word or something. Voila.
Try it yourself on the "redacted" copy of the Obama .pdf at
http://bit.ly/bAwmi7. It amazes me that people still get bit by this. Acrobat's "redaction" capability is a joke.