Some Facebook users struggled logging into the site and using features on their profiles on Tuesday.
Shut out of the social network, many took to Twitter to complain about the service issues.
"Facebook down...going to twitter to get my social networking fix," tweeted user @edwardasorpheus.
"Facebook's down. If this keeps up, expect cancer to be cured and the world financial crisis to be solved by the end of the day," another user, @findingnimesh, quipped.
According to diagnostic site DownRightNow, Facebook users can a "likely service disruption" this morning. Meanwhile, DownForEveryoneOrJustMe says that Facebook isn't down entirely, so users should probably sit tight and wait for regular service to return.
These problems come less than a week after a software glitch took down Twitter for several hours.
Have you had problems logging into Facebook or using the site today?
UPDATE: Service appears to have returned to normal around 11 a.m. ET on Tuesday.