UPDATE: (4:55 pm) Service appears to be coming back for some users. But you can see where Twitter users have been complaining.

UPDATE 2: Twitter is aware of the issue:

“Some users may be experiencing issues accessing Twitter. Our engineers are currently working to resolve the issue,” they say on the Twitter Status site.

ORIGINAL ARTICLE: It appears that Twitter is down for many users. Most of us in the office cannot access twitter.com (desktop or mobile), but the Twitter mobile app (iOS) seems to be working sporadically.

The site DownRightNow reports likely service disruption and many user reports of Twitter being down.

Twitter’s status site lists no site issue at the time, but we just noticed the outage a few minutes ago. The last major Twitter disturbance occurred last week (January 16th).

We’re joking with the Justin Bieber thing – kind of. We told you earlier today that he was just a few followers shy of surpassing Lady Gaga as the most-followed Twitter user. If he finally beat her, maybe beliebers broke Twitter?