So, it's not just me?
I sent an email to Dr. Martin's web site advising them that their father's work has been posted for all to steal. I haven't heard back yet, but I'm sure they will advise the webmaster that they need to remove his works. There is another Walter Martin book that I have been thinking about buying on that site along with some Norm Geisler Books I paid about $50 for (see tag line).
For all the sympathetic Calvinists out there, please note that Dave Hunt's book "What Love is This" is also posted for all to steal.
You never know, though. I recently found online some books by a couple of my favorite 1970s Russian science-fiction writers -- including one or two books I hadn't read and are not in my collection. But apparently the Moscow library somehow owns the copyright now...