Anonymous intercepts confidential conference call between FBI and Scotland Yard
The most likely explanation is that they didn't 'intercept' the call but simply dialed into the conference call system and recorded the call.The question then becomes how did they get the conference call dial in information?  Perhaps they managed to get into the email of one of the participants.  That would seem to be even more worrying than the interception of this single call.Also, on many conference systems I've used standing meetings use the same dial in information from week to week.  If this is a regular meeting it's possible that Anonymous has been listening in every week.