Two American web hosting companies Go Daddy and Network Solutions — have stopped registering domain names in China, citing the government's demands for personal information and photos of their customers.

Go Daddy announced its policy change at a Congressional hearing that was called to assess Google's decision Monday to stop censoring Internet search results in China. The search company's decision means that it will effectively abandon the world's largest Internet market after a four-year experiment.

Christine Jones, executive vice president and general counsel of Go Daddy, said the company's decision was not a reaction to Google, but instead grew out of concern about the security of its customers and "the chilling effect" of the new Chinese government requirements.

"This was a decision we made in our own right, based on our experience of having to contact Chinese nationals, collect their personal information and return that information to the government," Jones told members of the Congressional-Executive Commission China Wednesday, reading a nine-page prepared statement. "We made a decision we didn't want to act as an agent for the Chinese government."

Separately, Network Solutions announced Wednesday it had stopped hosting new web sites with ".cn" domains in December. The reason: The same as Go Daddy's.

Go Daddy, which been registering domain names in China since 2005, says it hosts many websites the Chinese government finds politically sensitive. The Scottsdale, Arizona-based company currently manages about 27,000 ".cn" domain names, which is just a sliver of Chinese web sites. The ".cn" names continue to be available through other resellers.

The China Internet Network Information Center, a quasi-government agency that styles itself as a non-profit, authorizes foreign companies to sell the ".cn" domain. It has always required firms collect customer names, addresses and other contact information but, in mid-December, CNNIC policy changed. Registrars are now charged with collecting color head shots, business information, and other details about doman-name applicants, which are to be shared with the agency. (Read CNNIC's press release here.) And there was more: The agency also required companies to get the personal information from existing customers and forward it. Refuse to comply, CNNIC warned, and we'll disable the websites.

Of the 1,200 customers Go Daddy contacted asking for the additional documentation, only about 20 percent supplied it, Jones said at the hearing, which was formally called "Google and Internet Control in China: A Nexus between Human Rights and Trade."

The company will continue to host the names it can, but won't register any new ones, Jones said. (She didn't reveal what fraction of the company's revenues China represents.) According to government data, China has 384 million Internet users – more than the entire population of the U.S.

Meanwhile, domain name wholesaler eNom hopes to continue selling in China – of the 11 million domains the Bellevue, Washington-based company manages, "tens of thousands are .cn domains" and the number is growing, Jeffrey Eckhaus, eNom's general manager, told Inc.

"We make no judgment on the restrictions themselves, rather we believe it is up to the individual to decide how much information they are willing to share to secure a domain," he said. As long as the Chinese want to buy, "eNom and our resellers will facilitate it." (Eckhaus noted that other countries, among them France and Spain, strictly control regulations for registering their country's domain names, though China is "reaching new levels.")

But he's worried the company hasn't heard the last word from China on registration restrictions. "If the process became yet more restrictive and required more labor on the part of the registrant than we would expect interest to drop and that could make it impractical for eNom to continue to support .cn registrations in China," he said.