The BBC has issued a fix to stop people downloading programmes from the iPlayer website that were intended for streaming on an iPhone or iPod only.
The iPlayer lets people stream BBC programmes
Hackers had discovered an exploit that allowed them to save the programmes to hard disk and share them with others.
Rights issues mean the BBC is only able to offer streamed programmes for up to seven days after broadcast.
A download service for PC users lets viewers keep the programmes for up to 30 days on their PC.
The Digital Rights Management on downloadable programmes from iPlayer was exploited and breached some time ago.
The BBC admitted that it was most likely facing a cat and mouse game with hackers intent on circumventing copy protection.
"It's an ongoing, constant process and one which we will continue to monitor," said the corporation in a statement.
"Like other broadcasters, the security of rights-protected content online is an issue we take very seriously," it added.
The BBC announced a version of the iPlayer for iPhone and iPod touch owners last week.
The content for the phones and iPod is streamed as an MP4 file without copy protection and hackers quickly realised that they could access the file using a simple plug in for Firefox.