Wow there are a ton of misinform authors on Facebook.
I've never heard of the site. I use Lendle, BookLending and Ebookfling. Lendle is probably is the most active but slow site. There is nothing piracy about these sites.
In the Amazon forums there are long threads of people requesting books to be loan to them. I think if Amazon had a huge issue they would of removed those threads a long time ago.