Not if the URL encodes the originator of the link, and all links tied to that user stop working when Nature flips a switch.

But regardless of what DRM scheme they choose, it's doomed to fail, all it takes is one person to crack the scheme and liberate the underlying documents. Alternatively, since 100 anointed blogs and media outlets will apparently have the right to download raw PDFs, all it takes is for one of their accounts to get hacked.