According to Domain Name Wire, Apple has filed a complaint with the World Intellectual Property Forum against 7 porn sites that include iPhone 4S in their domain name, including iPhone4S.com (!) which currently redirects to "Free Naughty for Mobile".
And really, you have to ask yourself why Apple didn’t proactively get that domain name before releasing the product. It was registered in August 2008, so someone else had the foresight to follow Apple’s naming conventions.
Indeed. Hopefully iPhone5S through iPhone 500S are now all safely registered by Apple's agents.
Source: Domain Name Wire