Nine human rights and on-line freedom organizations have publicly urged Yahoo! to end restrictions on users of its services inside Iran.

The groups asked Yahoo! in November to restore the ability of new Iranian users to register for its e-mail services and to download the Yahoo! Messenger Desktop Client. They released the letter on Thursday to publicize the case.

About 63% of users in Iran choose Yahoo! e-mail services, but in September the company modified its registration procedure for new accounts, requiring a phone number. However, numbers from several countries under US sanctions, including Iran, are neither listed nor accepted.

Yahoo! also does not allow the download of Messenger, an on-line voice and video calling service, from sanctioned countries.

The signatories to the letter say the restrictions violate the US Treasury’s General License D, issued last May, which authorizes export to Iran of information technology, including commercial services and software that are “incident to the exchange of personal communications over the Internet, such as instant messaging, chat and email, social networking, sharing of photos and movies, web browsing, and blogging”.

Yahoo! is far from the only US company limiting services to Iranians, despite the General License. Last October, we highlighted how large providers such as Google, GoDaddy, and Just Host were restricting their products. Because of the self-imposed limits, EA WorldView — recently unblocked in Iran — still could not be accessed by Iranians.

See Iran Analysis: When US Sanctions — and Not Tehran — Block Websites & Applications