Some document creators may feel that while conventional document security measures may protect documents from individual access attempts, they don't sufficiently deter subsequent, potentially successful attempts. Enter Locklizard Stingray, which literally "shocks" unauthorized users.
According to the site:
"The proposed approach of Lizard Stingray is to take DRM personal authentication controls a step further, by using a USB powered device that is capable of sending small electrical impulses to the finger of the current user in the event of an unauthorized action on a document (for example trying to copy or print a document when this has not been allowed by the publisher). In order to view documents, users must have authenticated by placing one of their fingers in the USB finger device (much like a pulse measurement tool) and keeping it there in order to view protected documents. The USB finger device is supplied free of charge along with the viewer software."
Packages start at US$5,000 for 50 users, and include the proprietary USB shocking device. Other supported deterrents include options to overpower the USB printer port or to override internal and external volume settings to sound a powerful, high-pitched fog horn alarm. You can read more on the Locklizard web site.
If it sounds to good/bad to be true, that's probably because it is. The most pertinent piece of information on the product release page is the posting date: April 1. Still, the idea of an electronic security system with practical deterrents is food for thought, isn't it?
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.