The Iranian government reportedly plans to begin blocking its citizens' access to Gmail, Google's popular e-mail service.
In its place, Tehran's state-owned telecommunications agency intends to establish its own, national e-mail service, though it is not immediately clear when.
The decision arrives in response to the wave of anti-government protests sweeping the country, all stemming from President Mahmoud Ahmadinejad's re-election last year. Organizers have frequently taken to such services as Twitter and Gmail to spread word of upcoming demonstrations, and Thursday's move is perhaps Iran's first attempt to stifle such dissent on the Web.
However, a spokesperson for the company declined to confirm to reporters whether the staggering halt to activity signaled Iran had blocked access to the site.
"We have heard from users in Iran that they are having trouble accessing Gmail," a Google spokesman told Reuters. "We can confirm a sharp drop in traffic, and we have looked at our own networks and found that they are working properly."
The State Department was similarly mum, but spokesman P.J. Crowley did reprimand the Iranian government for denying "its citizens access to information, the ability to express themselves freely, network and share ideas."
"Virtual walls won't work in the 21st century any better than physical walls worked in the 20th century. The Iranian people are dynamic and determined and will find a way to overcome the obstacles the Iranian government puts in their way."
White House Press Secretary Robert Gibbs also demurred the likelihood of such a block during his press briefing on Thursday.
"I think the president was very clear in his speech in Oslo, that he stands by the universal right of Iranians to express themselves freely," he said, adding that a number of states have similarly tried to quiet protestors by limiting access to social media.
Nevertheless, Iran's decision to block access to Gmail bears an eerie similarity to a similar dispute between the behemoth Internet company and China.
Reports earlier this year that Chinese officials hacked into e-mail accounts of the state's most well-known human rights activists prompted an international uproar, and later led Google to threaten to cease all operations in China.
An investigation into the alleged hacking is still underway, but the United States has nonetheless criticized the Chinese government for trying to stamp out dissent.
(This post was updated at 2:30 p.m.)