BT has confirmed that it limits peer-to-peer (P2P) file transfers for the collective benefit of its customers.
The news comes after broadband subscribers had reported difficulties watching online streaming media - which often uses P2P - at certain times of the day.
Now BT has stressed that the restriction of P2P speeds is necessary and that the practice is highlighted in its terms and conditions for broadband packages.
A spokesman for the provider told the BBC: "We restrict P2P speeds if it's having a negative impact on the online experience of the majority of our customers.
"We normally place restrictions in the evenings at peak time, but we do apply them during the day if a lot of customers are using P2P at the same time."
The number of broadband customers using P2P increased dramatically last month with the BBC's streamed coverage of the Olympic Games from Beijing through its iPlayer service.