ITmedia reports that Japan’s House of Representatives has just passed a revision to the country’s Copyright Law that could severely limit its citizens’ use of video sharing sites like YouTube and the Japanese-based Nico Nico Douga.

The revision is based on a 2010 revision to the Copyright Law which already made downloading pirated content illegal. Japanese attorney Toshimitsu Dan noted that the revisions now forbid ripping and copying of copy-protected and encoded materials, selling software and hardware that circumvents copyright protection laws and intentionally downloading illegally uploaded materials.

While the actual outlawing of illegal downloads isn’t such a big deal, it may still have a dramatic effect on Japan’s ability to tune in. The reason is that every time you watch a video on YouTube, your computer automatically stores a temporary download file in the browser cache on your hard drive. According to the new laws, such files could be construed as official downloads in Japan, leaving even the most YouTube-law abiding citizens subject to prosecution.

The new revision is also the first time that penalties have been assigned for such crimes. Offenders are now liable for up two years in prison or a maximum fine of 2,000,000 Yen (USD $25,106). The new provision will go into effect on October 1st.