A revision to Japan's copyright law to impose criminal penalties on those who illegally download music and movies has sparked debate in the country.

On Wednesday, Japan's parliament passed a measure to revise the law so that downloading is a criminal activity, punishable by up to two years in jail or a fine of up to ¥ 2 million (US$25,000). The revisions will go into effect from October. Currently violations are considered a civil matter.

The drastic increase in punishment for what could be as little as a single download was highlighted in the Japanese media. The Yomiuri Shimbun, Japan's largest newspaper, ran an article about the law Thursday with a headline that read "Even one click is now a crime?"

While online streaming and download services like Hulu and iTunes are popular in Japan, sales and rentals of physical CDs and DVDs are still common. Years after U.S. video rental firms like Blockbuster went bankrupt, Japanese equivalents like Tsutaya are still widely used.

The Recording Industry of Japan, a powerful music trade group, immediately applauded the new measure, and said it would work to inform people of the new penalties.

"This revision will reduce the spread of copyright infringement activities on the Internet," said Chairman Naoki Kitagawa, who is also the CEO of Sony Music Entertainment Japan.

But the Japan Federation of Bar Associations, a widely respected legal group, said that the law treating downloads as a civil matter, which was adopted in 2009, should have been given more time for its effectiveness to be judged.

"Treating personal activities with criminal punishments must be done very cautiously, and the property damage caused by individual illegal downloads by private individuals is highly insignificant," the group said in a statement.

A study published by the Recording Industry of Japan found that in 2010 about 4.36 billion such files were downloaded illegally, about ten times the 440 million files that were paid for. The study found that in Japan, dedicated video download sites are far more popular than peer-to-peer software, which can be harder to trace.