In general, crime prevention is a good thing — it helps stop crime. By punishing people for minor transgressions, you stop them from committing larger misdemeanors and discourage crime overall. If the principle is applied blindly, however, it can produce some awkward results.

Tokyo police raided the home of journalist Kosuke Tsuneoka in Nakano Ward on Oct. 6 on suspicion he had a role in assisting a student who reportedly wanted to go fight for the Islamic State group in Syria. Tsuneoka is believed to be acquainted with an Islamic State military commander.

"(Police) raided his home Sunday and confiscated everything that contained data, from PCs, USB memory sticks, cameras, mobile phones — just about everything," The Japan Times quoted Hitoshi Takase, a friend of Tsuneoka, as saying. "Tsuneoka thinks the police see him as having a key role in taking the student to Islamic State, or that they want to obtain information about Islamic State from him."