Today, Twitter announced that a glitch caused some user passwords to be stored in a readable, clear text on its internal computer system. According to Twitter, the issue has been resolved and there are no signs of unauthorized access or misuse of the information.
Nonetheless, all Twitter subscribers should change their password and enable login verification. You can learn more at Twitter's Blog Post. Additionally, you can read more on the subject at the New Jersey Cybersecurity & Communications Integration Cell's website Be Sure to Secure Your Twitter Account.