Twitter mistakenly told thousands of users that their accounts had been hacked Monday night.
Emails sent from email@example.com told the Twitter users that their accounts "may have been compromised by a website or service not associated with Twitter." The email also instructed them to create a new password, saying that Twitter had proactively reset their login credentials.
Twitter(TWTR) confirmed Tuesday that those emails were sent by accident.
"We unintentionally sent some password reset notices tonight due to a system error," said Twitter spokesman Jim Prosser. "We apologize to the affected users for the inconvenience."
Prosser declined to comment about how many were affected, but thousands of Twitter users angrily tweeted about the incident Monday night.