(4) Producer does not include persons whose activities relating to the visual depiction of actual sexually explicit conduct are limited to the following:
...
(iv) A provider of web-hosting services who does not, and
reasonably cannot, manage the sexually explicit content of the computer site or service; or
(v) A provider of an electronic communication service or remote computing service who does not, and reasonably cannot, manage the sexually explicit content of the computer site or service.
Reference:
http://my.execpc.com/~xxxlaw/2257Tables5.24.05.htm
Wouldn't that make a US web hosting company simply providing a server for someone exempt from being charged with anything?