Ben Dover Productions, which makes porn films, will soon be sending warning letters to O2 customers who have been suspected of illegally sharing its films on the network.
O2 was forced to pass on the customer details of 9,124 IP addresses, which had carried out illegal downloads, to the production company after it won a court order in March.
The High Court has approved the content of the letter that will be sent out, according to the BBC.
Ben Dover has said it will target users who had uploaded films to others, but not people who had just downloaded one film.
"In our first letter we seek to find out more information regarding evidence of an infringement of our copyright," Julian Becker, Ben Dover's commercial director, told the BBC.
"Depending on the response to our letters we will then decide our next action."
If recipients of the letter do not reply within 28 days, they could be found liable for the copyright infringement.
The letter is expected to advise them on what steps to take to negotiate a settlement amount, which the court has ruled should be individually agreed with each defendant.
According to the BBC, the High Court made sure that the wording of the letter was reasonable before approving it, for example, telling the company that it could not specify compensation of £700 and that it could not tell users that their internet connection would be slowed down or terminated if they did not comply.
O2 said in a statement: "We are pleased that the court has taken a robust approach and controlled the tone and content of the letter Golden Eye [the registered name of Ben Dover Productions] proposes to send to our customers.
"We are also pleased that the judge acknowledged the unique position we are in, and agreed that we have approached this issue in a reasonable way."