Downloading movies and TV shows from the net is something some foreigners living in Japan do to get a taste of home or kill a little time while they hang out in the apartment, with little space to do much else.

Now, though, they’d better be even more careful about making sure the source is a legitimate one, with new revisions to Japanese copyright law, announced this week, meaning that downloading material from, or making, copied DVDs will be a criminal offense.

In fact, it is the knowing downloading which will be the offense but it is unclear how easy that will be to prove or disprove. Torrents, and the pirate sites that host them, are pretty obviously bending and breaking rules, but how about web-streaming services? Is the average web user always clear about the law?

Or is that a naive way to look at it? Maybe we should question the philosophy that everything available for free is there for the taking.

Maximum penalties of two years in prison are not light but compare them to those faced by uploaders… They could be charged and made to spend up to ten years behind bars and fined up to ten million yen.

Some people are worried that the law will lead to unnecessary prosecutions, the Japan Times quoting upper house member Yuko Mori as saying “We shouldn’t risk making the general public — including youths — the subject of criminal investigations.”

Tech site Wired quoted Japanese attorney, Toshimitsu Dan, as having told IT Media that “even watching a YouTube video could be grounds for arrest ‘if the viewer is aware that downloading [such material] is illegal’.”

We have been warned, the new penalties will come into effect in October 2012.