Didn't they sell a "license" at some point, that made your Linux installation "legal"?
Also, this! (snip added):
> The license, called the SCO Intellectual Property License for Linux, lets Linux users run SCO's intellectual property in binary form only. "It gives you a license to run the software only. You can't view the source, and you can't contribute it to an open-source product for everyone's use, [...] This is a license that is designed to run in addition to the GPL," he said.
What?! How on earth can you say this with a straight face!
That's not much, it's in fact really cheap for a Unix.