TORONTO -- Twitter Inc. is encouraging its 336 million users to change their passwords after a bug left some exposed in an internal log.

The company says it typically uses technology to mask the passwords so no one can see them, but a glitch caused them to be available in plain language.

Twitter says it has no reason to believe any of the passwords left its system and an investigation found no breaches or misuse of the data.

Twitter discovered the bug itself and says it has since been fixed.

It removed the exposed passwords and implemented plans to prevent the bug from occurring again.

Twitter says it is only asking users to change their passwords "out of an abundance of caution."