Basically, their system doesn't prevent someone from sharing their "link key" on a public web site, so it is no more effective than any other DRM system. They are depending on people being unwilling to share, according to fear of prosecution (assuming the key can be traced to the person who released it). We already know that assumption is a bad one.
This idea yawns. There are better ways to enact document security (
think biometrics!).
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