Google's popular built-in email chat client, Google Talk, colloquially known as "Gchat," suffered a massive outage early Thursday that impacted "a majority of users," the company reported at 6:50 a.m. 

ET. Four hours later, Google said that "service has already been restored for some users, and we expect a resolution for all users in the near future," but said that the esimate of service restoration was subject to change.