Initially, the Karelog software could also display phone call logs. In addition, it was difficult for owners of smartphones to notice that the software has been installed in their handsets.

Although the company officially says the software should be installed only with the smartphone owner’s permission, it is possible for others to install or use the Karelog software when the owners are away from their smartphones.

The company took part in editing a book promoting the software. The book promotes the app by saying, “You can trace and check what your lover is doing now,” and even, “This is the ultimate application for stalking.”

The word “kare” in the app’s name means boyfriend in Japanese.

On Sept. 5, U.S. information security firm McAfee Inc. designated Karelog a “suspicious program,” saying the product can transmit personal information to third parties without the smartphone owner’s consent. However, McAfee later rescinded the designation.

Manuscript has been the target of much criticism since the software was released. Many people complain the software infringes on privacy.

On Aug. 31, Manuscript posted a message of apology on its website and discontinued part of the service, including the display of phone call logs.

The company also altered the app so that smartphone owners can notice more easily if the Karelog software has been installed.

The company plans to offer the software free of charge until Sept. 30.

According to information security firm Symantec Corp, there are similar apps for tracing users’ actions in other countries.

In the United States, such software products enable users to check the contents of short emails and Web sites the handset holders have accessed, as well as viewing whereabouts and phone call logs.

Websites selling such software products explain they can be used to monitor the actions of family members or employees.

Also, for several years there have been cases overseas of smartphones being infected with computer viruses that steal data, including users’ whereabouts.

Legal experts’ opinions are divided over whether it is illegal to install such tracking apps without the consent of smartphone owners.

Professor Hisashi Sonoda of Konan University’s Law School, a researcher in criminal law, said the software “can be regarded as a computer virus which collects records of actions against the will of users.”

Sonoda said: “It’s possible that developers and operators are committing the crimes of producing and providing computer viruses. People who installed the software without the smartphone owners’ consent may face a charge of abetting such crimes.”

But Yoji Ochiai, a lawyer who was formerly a prosecutor, opined that using the software does not constitute production of a computer virus or other such crimes.

“The software products do not work in a way different than explained. We can’t say they are computer viruses,” he said.

However, both experts shared the view that using the software without smartphone owners’ consent constitutes infringement of privacy.

The Internal Affairs and Communications Ministry is closely watching the controversy.

Its guidelines about personal information in telecommunications businesses stipulate that a user’s whereabouts must not be provided to third parties without the user’s consent or a court warrant.

At a press conference on Tuesday, Internal Affairs and Communications Minister Tatsuo Kawabata said, “Disclosure of personal information without consent is something that should not occur.”

(The Yomiuri Shimbun)