5fad.com, one of the largest online music websites in China, says that Sina.com (SINA) has violated 5fad's colorful ringtone copyright.

5fad says it will seek legal remedies if Sina.com does not immediately stop the infringement.

A representative from 5fad.com says that Sina.com had placed many of 5fad's originally-created colorful ringtones on its platform and even changed the singer of some songs and sold them to mobile service providers without 5fad's authorization.

5fad.com says it asked Sina.com and other violators to stop the infringement immediately. However, none of the parties responded to its request.

5fad.com was founded by Zhejiang Fanya E-commerce Company in May 2005. It has signed over 1000 singers and the company claims to have taken up 80% of the originally-created Chinese online music market.