The Motion Picture Association of America's (MPAA) campaign against movie piracy has taken another turn after it confirmed it was suing two chip makers.
The MPAA is very concerned about movie piracy
It has alleged that the two DVD chip firms supplied makers of equipment that
could be used to copy DVDs.
It said the chips were being sold to companies whose DVD players did not have what it said were "appropriate security features."
The legal action was filed in California's Superior Court.
The two companies, Taiwan's MediaTek and US-based Sigma Designs, make chips which decode a program called the Content Scramble System (CSS). They have made no comment about the action.
CSS is the common copy-protection software used to prevent DVDs being duplicated.
The licenses which the firms have stipulate that they are only permitted to sell the chips to other companies which hold CSS licences.
MPAA's concern is that selling to non-licensed manufacturers could encourage the illegal copying of DVDs.
The MPAA says the movie industry, for which it is the representative umbrella body, loses billions each year because of movie piracy.
Last year, it tried to stop a Norwegian, Jon Lech Johansen - nicknamed "DVD Jon" - from distributing a program on the net that could break CSS security codes.
He had created the program, called DeCSS, in 1999 at the age of 15.
Norwegian courts twice ruled that he could not be charged for "breaking" into DVDs he had legally bought, nor for creating a program others might use illegally.
Earlier this month, the MPAA successfully fought a legal battle to prevent a software firm, 321 Studios, from selling its DVD X Copy and Games X Copy programs.
They too circumvented copy protection systems, but 321 Studios said it had developed the programs so that customers could back up their own DVDs and games.
But the MPAA and games industry argued the programs infringed the Digital Millennium Copyright Act.
321 Studios collapsed after repeated legal action.
And in July, a California court placed an injunction on ESS Technology preventing it from selling its CSS-decoding chips to unlicensed manufacturers of DVD players.