A Japanese-language input program — potentially installed on millions of computers, including those used at government agencies — sends every character typed to the software provider's server without the user's consent.

The Baidu IME program for Windows computers is distributed for free on the Internet by Baidu Japan Inc., the Japanese arm of China's Baidu Inc., operator of China's most popular Internet search engine.

Baidu Japan says the program, often installed with other downloadable software, is used by 4 million people.