That broad definition would cover individuals, coffee shops, libraries, hotels, and even some government agencies that provide Wi-Fi. It also sweeps in social-networking sites, domain name registrars, Internet service providers, and e-mail service providers such as Hotmail and Gmail, and it may require that the complete contents of the user's account be retained for subsequent police inspection.
The definition of which images qualify as illegal is expansive. It includes obvious child pornography, meaning photographs and videos of children being molested. But it also includes photographs of fully clothed minors in overly "lascivious" poses, and certain obscene visual depictions including a "drawing, cartoon, sculpture, or painting."