Hollywood film studios are to sue
people who swap pirated copies of films over the internet.
Dan Glickman announced the measures on Thursday
The Motion Picture Association of America (MPAA) said the civil suits would seek damages of up to $30,000 (£16,300) per film.
Dan Glickman, head of the MPAA, said the lawsuits were necessary before high-speed internet access made downloading pirated films easier.
The MPAA said it would file hundreds of lawsuits from 16 November.
"This was not an easy decision, but it must be done now before illegal online file-sharing of movies spins out of control," said Glickman.
"Illegal movie trafficking represents the greatest threat to the economic basis of movie-making in its 110-year history."
The crackdown will target individuals who deal in illegally copied cinema products on file-swapping networks, as well as the pirates themselves.
Glickman added: "People who have been stealing our movies believe they are anonymous on the internet, and wouldn't be held responsible for their actions.
"They are wrong. We know who they are, and we will go after them, as these suits will prove."
The MPAA claims the US film industry loses more than $3bn every year in potential global revenue because of piracy.
But Glickman said the figure did not take into account the losses from thousands of illegal online downloads that were swapped every day.
The MPAA represents the seven major Hollywood film studios.