Twitter invited its users to change the password to log in because of an error in the system of storing passwords.
"When you set a password for your Twitter account, we use technology that masks it so that no one in the company can see it. Recently, we found an error, because of which the passwords were stored unmasked in the internal journal. We have corrected the error, there are no signs of penetration or misuse (passwords) by anyone, "the company said..
"As a precaution, think about changing the password on all services, where you used this password," the message says..