A revision of the Code of Criminal Procedure enacted in 2004 prohibits lawyers and defendants from showing or handing copies of evidence they have received from the prosecution to third parties. It also prohibits posting such copies on the Internet. When the revision bill was submitted to the Diet, the Japan Federation of Bar Associations opposed it, saying it would not only diminish the right of defendants to defend themselves but also run counter to the freedom of the press and the principle of a trial being open to the public. The Japan Newspaper Publishers and Editors Association also criticized the bill, saying it could lead to restriction of reporters' news gathering activities.

What these organizations feared is now happening. In the past, reporters were able to view materials such as an investigator's record of a suspect's oral statements if they established a relationship of trust with lawyers. But these days it is impossible for reporters to do so, because lawyers fear falling victim to the harsh penalties contained in the revision. Violators, including former lawyers and former defendants, face imprisonment of up to one year or a fine of up to ¥500,000.

Under the revision, public prosecutors can present evidence to lawyers before the start of a trial and both parties can narrow down the points of contention — a system designed to shorten the time needed to complete a trial process, which will be necessary when a lay judge system is introduced next year. Along with the introduction of the system, penalties were introduced to prevent the passing of copies of evidence to third parties.