AVN has the following summary and a link to the full details:

Senator John McCain (R- Ariz.) has drafted a legislative proposal imposing fines of up to $300,000 on websites which fail to report illegal images.

McCain’s proposal, known as the “Stop the Online Exploitation of Our Children Act”, broadens existing legislation for Internet service providers to include… “any Web site with a message board; any chat room; any social-networking site; any e-mail service; any instant-messaging service; any Internet content hosting service; any domain name registration service; any Internet search service; any electronic communication service; and any image or video-sharing service…”