Update 2: As of 1:25 a.m., T-Mobile says everything's back up and running.
If you're on T-Mobile, chances are you know this by now, but the company is reporting it's in the middle of what's sounding like a pretty big outage. From its Twitter feed:
All – We’re aware of the current service disruption. Our rapid response teams have been mobilized to restore service as quickly as possible. We will provide further updates as more information is available.
Stay tuned, folks.
Update: T-Mo says at 9 p.m. EST, only 5 percent of its customers were still down.