RIPA and file-sharing??

[Peter Fairbrother]

PlusNet blame RIPA for revealing IP addresses:

http://community.plus.net/trafficmanagement/2007/11/28/file-sharing-letters

"An example would be where English law dictates a different path, and 
specifically considering the issue of file sharing, the Regulation of 
Investigatory Powers Act (or RIPA) is relevant. [..] Amongst its powers 
under RIPA, the High Court can request from an ISP details about 
particular customers."


AFAICT, while it doesn't prevent it, RIPA doesn't give the Court any 
such power.

Anyone know under what authority such demands are issued?


Ta,

-- Peter Fairbrother