I go to a site. They sell me / give me free PLR articles/eBooks. How do I know if they didn't ripped the content from somewhere and packed as "new"? If I use CopyScape, and those articles are on 10 sites, with 10 different authors, how do I know which is the real author? Just because the PLR articles I have pass CopyScape, does it mean that they are unique? If the PLR is actually copyrighted content, if I get sued, can I point to the source where I've downloaded the PLR?
I go to a site. They sell me / give me free PLR articles/eBooks. How do I know if they didn't ripped the content from somewhere and packed as "new"? You don't. If I use CopyScape, and those articles are on 10 sites, with 10 different authors, how do I know which is the real author? No way to be sure. Just because the PLR articles I have pass CopyScape, does it mean that they are unique? No. CopyScape can catch many duplicates, but you can certainly be guilty of copyright infringement on content that "passes" CopyScape. If the PLR is actually copyrighted content, if I get sued, can I point to the source where I've downloaded the PLR? No, the website owner is responsible for all content they place on their site. You are liable for damages. If you are sued, you can try to sue the person who sold you the content to recover what you had to pay.