Online security firm accused of stealing user info (3)

Not the first time

"If a company attracts too much controversy, it would certainly affect its development," said Li from Analysys International.

Qihoo has experienced similar problems before, said Tao Ran, an analyst with Snowball Finance, an Internet-based financial services company.

In 2010, it became embroiled in a battle with Tencent. The two firms accused each other of stealing users' private information, uninstalling or blocking each other's applications and unfair competition.

Following a court verdict in April 2011, three Qihoo-related firms were required to apologize to Tencent and pay it compensation of 400,000 yuan for slander and unfair competition.

The legal battle resumed in April 2012, when Qihoo sued Tencent for abuse of dominant market position, and Tencent filed a counter-claim against Qihoo. The court has yet to deliver a verdict.