Why not just alert whom ever still owns the IP of these games of what he is doing to shut it down?
Depending upon the size of the original IP holder ...
[ul][li]is the legal dept on-staff or external?[/li][li]how busy are they?[/li][li]how far up the management chain does a decision on how to respond go?[/li][li]how many meetings and man hours is it going to take to get that decision?[/li][/ul]
Sometimes, the reality is that no one knows who actually owns the IP. That, in and of itself, becomes problematic. Xak III was developed and published by Microcabin and NEC. It isn't always clear which retained intellectual property rights. Hell, they may not even know if they own it.
Assuming it was NEC, they got out of the video game business 20+ years ago. They would have zero financial interest to pursue anyone violating a copyright on game software they hold. You could end up emailing everyone from the CEO to their legal department to their janitorial staff, and not find a party even interested enough to send a basic C&D.
If it was Microcabin... the situation is even more messy. They were bought by AQ interactive, and then AQ sold 85% of their stake of Microcabin to "Fields Corporation." Who owns the actual IP at that point? And once again, would you find anyone at the company even remotely interested in protecting IP that is from a defunct subsidiary? Maybe.
Victor Ireland talked at length about the difficulties in bringing over and securing IP in an old Retronauts podcast:
http://n4g.com/news/986536/1up-retronauts-podcast-victor-ireland-talks-about-the-rise-and-fall-of-working-designsUnfortunately, thanks to the destruction of 1up, that link won't take you to the actual podcast. However, its a great episode, and worth a listen. He had a helluva time trying to figure out who owned IP, and that was for a legitimate purpose, his day job. Trying to track down a defunct IP owner to cause hell over a small repro run is going to be more difficult.