Some other things I didn't mention but would like to. Much of which is regarding actually selling stolen material. I'm not going to name names, but what I say can be looked up.
Amazon kindle books is awash with piracy of our industry (and others). There are 100's of guitar tab books on kindle from a certain individual, and for almost any guitarist under the sun. Not a single one has a publisher name or copyright statement inside, just professional tabs that look like they have been lifted then sold on Amazon. Another book promo vid uses music from a famous guitarist, and even if the author played it, he didn't write the tune.
I contacted the legal department of the huge publisher who I know own the copyrights but never heard back and it's still rife on Amazon, I guess they have bigger fish to fry? no idea. I noticed one of the guys stuff who looks to have had their stuff nicked is a JamTrack Central artist.
As the law stands Amazon would have to take this stuff down only if a DMCA take down request was made. If amazon don't know about it / aren't told then they are not liable and neither do they have any responsibility to make sure it doesn't happen in the first place. It would be hard to argue websites should be held liable for copyright infringements from content they don't publish themselves, this might open vague interpretation for websites that genuinely try their best to police, pre-DMCA take down.
I made a DMCA takedown request before and after my work was taken down (a book) the website had a system to recognize further infringements of the same work and stop them automatically, which is good faith, I'm not sure they are legally obliged to do that. I think the technology is there, A.I. can recognize cat vids on youtube.
For anyone interested this is an example of a legal copy of someones work, if you view the look inside there is a publisher statement and a copyright statement (the bit that tells you copying without holders permission is illegal), the Publisher is also listed in the product details:
http://www.amazon.co.uk/Maiden-Anthology-S...DV7FCWA74KHTG9RThere are many kindle books with pro tabs in that have neither of the three. If you are a fan and want to support your musician whether famous or not, wealthy or poor, then you should be aware of this, and I'm certain your support is much appreciated.