Correction... Tarbell has been, to my understanding, re-established. I know that a Canadian company owns the rights to distribute Tarbell in it's original format (a series of correspondence courses akin to the original 13 Steps) and supposedly these will be coming to market sometime this spring. I also believe that Christopher @ Lybrary.com owns the digital rights to Tarbell when it comes to publishing.
Royal Road I'm not certain of but given the greed that powers our industry these days, I'm certain someone has grabbed up the publishing right. . . this is happening with more and more "out of date" material.
There are a plethora of Torrent sites out there however, who have very long lists of hard to get magic publications including those that were produced on a limited release basis. Obsidian Oblique for an example, has been found in well over a dozen sites in the past year when there are less than 200 legal copies in distribution (way less) and too, the originals included a video which you can't get via the pirate forums.
Authors & Publishers are always trying to pull down their materials and typically this is fairly easy with the exception of sites based in Mexico, China and other parts of Central America. The piracy is so bad in those countries that many now refuse to sell to them unless they really know the person that's buying.
Last year I penned two controversial articles for VISIONS on piracy. The controversy centered on "when is it piracy" and my personal view centers on it being such when it is done in a mass production manner such as we find on eBay where copies are being sold as originals or on the File Share networks in which material is used like currency. Sadly, we find this same sort of horse trading on certain forums, the Magic Cafe being one of the more notorious; so much so that one gent that Rick Maue and I caught red handed is now a moderator there, though he was outed as a thief. That forum has a long history of "looking the other way" when it comes to knock-off artist, though.
The moral of the story is simple though, if it looks too good to be true it probably has a skeleton near by, so question it. Illegal downloads are frequently carriers for files that have nothing to do with the thing you were looking for and likewise open the door for all kinds of spam, so be aware.