LONDON — They trade jokes, chuckle and talk shop about a hacker plot called "Project Mayhem."
But at the heart of the conference call between the FBI and Scotland Yard was a strategy aimed at bringing down the hacking collective known as Anonymous, which has launched a series of embarrassing attacks across the Internet.
Unfortunately for the cyber sleuths, the hackers were listening, too — and now so is the rest of the world.
Anonymous published the roughly 15-minute-long recording of the call to the Internet early Wednesday, gloating in a Twitter message that "the FBI might be curious how we're able to continuously read their internal comms for some time now."
The FBI said the information "was intended for law enforcement officers only and was illegally obtained" but that no FBI systems were compromised. Scotland Yard said that they'd seen no immediate information that their operations had been compromised — but that the force was still checking.
The bureau said that "a criminal investigation is under way to identify and hold accountable those responsible."
It's not entirely clear how the hackers got their hands on the recording, which appears to have been edited to bleep out the names of some of the suspects being discussed.
Amid the material published by Anonymous was an email purportedly sent by an FBI agent to international law enforcement agencies. It invites his foreign counterparts to join the call to "discuss the ongoing investigations related to Anonymous ... and other associated splinter groups." The message contained a phone number and password for accessing the call.
The email is addressed to officials in the U.K., Ireland, the Netherlands, Sweden and France, but only American and British officials can be heard on the recording.
Graham Cluley, an expert with data security company Sophos, said that hackers must have been able to eavesdrop on the call because they had compromised the investigator's emails.
"The hackers knew the phone number, they knew the time, they knew the passcode," he said in an email. "Even my ironing lady could have rung in and silently listened to the call just like Anonymous did."
He said that the fiasco was "highly embarrassing for the cops."
"Who knows what other information, the hackers might have been able to scoop up?"
An email to the FBI agent who sent the email was not immediately returned, while one of the British investigators on the call referred questions to Scotland Yard's press office, which confirmed that it had an investigator on the call but said it would be making no further comment.
The recorded discussion itself appears sensitive. Those on the call talk about what legal strategy to pursue in the cases of Ryan Cleary and Jake Davis — two British suspects linked to Anonymous — and discuss details of the evidence gathered against other suspects.
Amid jokes about a teenage hacking suspect and light-hearted banter about McDonalds, the investigators seem to discuss whether to delay the arrest of two hacking suspects in order to give the FBI more time to pursue its side of the investigation.
Karen Todner, a lawyer for Cleary, said that the recording could be "incredibly sensitive" and warned that such data breaches had the potential to derail the police's work.
"If they haven't secured their email it could potentially prejudice the investigation," she told The Associated Press.
Anonymous is an amorphous collection of Internet enthusiasts, pranksters and activists whose targets have included the Church of Scientology, the music industry, and financial companies such as Visa and MasterCard.
Following a spate of arrests across the world, the group and its various offshoots have focused their attention on law enforcement agencies in general and the FBI in particular.
Raphael Satter can be reached at: http://twitter.com/razhael