Even though they have at most just 140 Chinese characters, original micro blog entries are protected by copyright and reposting them without authorization is infringement, said judges and delegates from major domestic micro blog operators at a recent seminar in Beijing.

In the first quarter of this year, one of the nation's top micro blog operators Sina Weibo received more than 1,500 online complaints from users along with 60 letters from lawyers about infringement. But that is "merely the tip of the iceberg", said industry insiders.

Zhang Qinkun, senior manager of legal affairs at Tencent, another influential micro blog operator, told Guangming Daily that there is huge potential for infringement on micro blogs due to their wide range and high speed.