According to The Verve  Hackers appear to have breached a Yahoo Voice server and posted around 453,000 user accounts and passwords online.

D33Ds Company, a hacking group, made a file available on Wednesday with the credentials visible in plaintext. 

Ars Technica managed to obtain a statement from the hackers, explaining their motive. "We hope that the parties responsible for managing the security of this subdomain will take this as a wake-up call, and not as a threat," reads a note attached to the file. The group also explain that other holes have led to disclosures in the past and that Yahoo should "not take them lightly."

If you're a Yahoo user, even if you don't use the Voice service, then now is a good time to change your password.