My Prosper.com experience

Prosper operates an online lending platform connecting borrowers with lenders. The loan notes issued by Prosper pursuant to this platform are securities and Prosper, from approximately January 2006 through October 14, 2008, violated Sections 5(a) and (c) of the Securities Act, which prohibit the offer or sale of securities without an effective registration statement or a valid exemption from registration.

http://www.sec.gov/litigation/admin/2008/33-8984.pdf