Looking on the web for some ebooks for sale in the right format (EPUB for me), I have been amazed by the number of sites pretending to offer them for free download, even though these are in copyright commercial books. Some others offers books at a very low price.
I am aware that some authors (notoriously Cory Doctorow, for example) allow that, but it seems still to be the exception rather than the rule.
My last attempt was when searching for
"The A.I. Chronicles" Peralta epub
What is hiding behind these sites?
How do I know which sites are actually conducting a legitimate business?
For example, I found on http://www.mobileread.com a pointer to a site https://www.humblebundle.com/, selling book bundles at a low price, for example a sci-fi bundle. Though old, they are all books under copyright, AFAIK.
How do I know whether the site is conducting a legitimate business? What are signs that distinguish a scam from a legitimate low price seller?