The International Center for Missing and Exploited Children says 99 countries in the world still do not make possession of material showing children in sexual activities a crime.
But now, Japan's parliament has changed that number.
Japanese lawmakers have approved a measure that makes possessing such material a crime. The move comes after many years of international pressure.
Filipino children show signs against child pornography during the start of a nationwide alliance to combat the growing problem in the Philippines.
Some content may be disquieting.
Pornography – often called porn -- is described as printed or visual material showing sexual activities. Child pornography is pornography showing children during these acts.
Under a new Japanese law, people found guilty of possessing child pornography will be jailed for up to one year. Or, they will face financial punishment of about $10,000.
Until the law passed, Japan had been the only remaining major developed country that had not banned possession of child porn. It outlawed production and distribution of such material in 1999. But making possession a crime took much longer.
And nobody knows that better than a man named Ernie Allen.
Mr. Allen is president and chief executive officer of the International Center for Missing and Exploited Children. He says his agency worked with Japanese officials for years to bring about this new law.
"Ninety-nine still don't criminalize possession. And they are overwhelmingly countries in Asia, Africa and the Middle East. All of Europe now criminalizes possession of child pornography. All of North America (criminalizes possession.) ... And we hope that Japan will now be viewed as a leader in this area and can help influence other governments, other parliaments to take action."
Japan did take longer than other countries with similar economies to make reforms. But Mr. Allen says he hopes Japan will cause further changes around the planet, especially in Asia and Latin America.
Mr. Allen names what he calls "significant countries" that still do not criminalize owning child pornography such as China, Russia and Argentina.
Los Angeles Police Department detective Shannon Geaney searches a suspected child pornographer's computer.
He explains how his agency has seen the child porn problem explode, or grow very quickly, around the world.
In 2002, the Center for Missing and Exploited Children started a Child Victim Identification Program. They asked law enforcement agencies from around the world to send images they received of exploited children.
"(In) 2002 there were 50,000 images. By 2005 the Center had received 1.9 million images. Last year alone the Center received and reviewed (considered) 22 million images and video. That's how much this problem has exploded around the world because of the advent of the Internet."
The high numbers can be disturbing. But Mr. Allen says there is also a big increase in the number of countries who have enacted child porn laws or elements of such laws.
The new law in Japan is expected to take effect next month. However, punishment for owning child pornography will not be enforced for a year. The reason: Japan says it hopes that many people will dispose of the material on their own.
I'm Anna Matteo.