This is the topic you're thinking of, jimbo--
Dark Shadows complete dvd set on Planet DVD
You probably couldn't find it because the company has changed its domain name (actually, a 3rd time-- hmm, could bad online reviews posted on various sites have anything to do with that?). The link to PlanetDVDHouse in the topic started by Cassandra Blair no longer works, though the DS set is still listed on PlanetDVDStore.com.
Regarding your question about whether it's legal, I don't know because on one hand their terms and conditions are spelled out for consumers, yet I suspect that MPI would not be pleased if their DVDs were being duped and sold.