I don't see why this is being called DRM. it has nothing to do with protecting copyright and everything to do with protecting corporate secrets.
This kind of system is already in use in some high security installations, generally by marking secure documents with a distinctive symbol that document management systems recognize. Photocopyers, particularly modern units that fax and scan to email, are a big way that secrets can make it out of a corporation accidentally. This technology isn't supposed to stop anyone that's intentionally trying to sneak documents out, it's to stop the real user that makes a mistake (doesn't realize a document is sensitive, takes the wrong paper to send, hits the wrong button on the machine...). It's just a simple system to make users with a document that is potentially sensitive stop and think before emailing it to the bank/aunt ellis/nigerians. When this sort of system is implemented it requires oversight to work effectively, because there will be many false positives. It's just the cost of the added security. No doubt the PDFs sent to a monitor will be used more often to make it easier to put through an authorized false positive (email the PDF instead of having to scan the doc again) than to find someone to punish.