Hi OT.
I’m not saying you’re stealing; I’m saying the website has some copyrighted material and/or Intellectual Property (IP) which belongs to the creator/author/artist NOT to the public.
To the best of my knowledge, neither Huey nor Lang released their books to the public domain.
Unfortunately, because of piracy as well as different countries having different laws protecting IP, it’s each individual’s responsibility to make certain whatever they take (read, download, whatever) is legitimate and legal.
Otherwise, the individual is a thief just as if they went into a retail store and stole a book or a DVD.
If someone downloads a book and there’s a Copyright statement in the book, usually at the very beginning, then it’s not public and should be deleted immediately. Otherwise, again, it’s theft.
It’s really quite black and white.