The pirating thing (scans available on the web) is such a huge issue. For example, if you know how to look for PDF's online you can find a lot of people with unprotected, but unlisted, servers/web sites with all kinds of stuff on them - and they are the ones who don't even realize they are contributing to pirating. Funnily enough I tracked down a copy of my own book in this manner since I couldn't get it from the old ICE and I didn't really feel like scanning the thing myself (I figured I own like a dozen copies and wrote it to boot, so I didn't feel too bad about downloading it).
I've debated 'protection' on electronic copies of things with more than one company, but it will always come down to if they are willing to actually go after people for the piracy - which most RPG companies cannot afford to do. Steve Jackson Games used to state (not sure what their position is now) they were not worried about it because they had seen no decline in sales of their hard copies after the electronic copies were available... but that seems somewhat short sighted to me. The upside is someone can look at your (pirated) stuff before they decide if they want to buy it, so it COULD increase sales of hard copies to a limited extent. But, in my experience, people either want a hard copy or they don't. The cost involved in printing out full RPG books, combined with the hassle and quality issues, usually just isn't worth pirating a scan just to print out. So, imo, in reality they simply have no idea how many ELECTRONIC copies of their books they are missing out on sales for because it doesn't necessarily have that much to do with the hard copy sales... and in the future this will become a bigger and bigger issue. All just my own speculation though.
But, I'm not a fan of PDF's of RPG books. A novel I'll get an electronic version, because I can just read it on a tablet, but I want hard copies of my RPG books so they can be passed around the table, spread out for cross referencing, etc. The only reason I've found I like PDF's is because I can use them to print out portions of books in order to make my own. I have six individual binders for: Professions, Races & Cultures, TP's & Skills, Talents & Flaws, Open/Closed/TP Spell Lists, and Base Spell Lists. Last one I need to make is for Attack & Critical Tables, I just have not bothered because players keep copies of the ones they need in their own character binders. They are used extensively in character creation and a few are used for reference during play.