Microsoft has combined technology with a legal manoeuvre to cripple a massive network of hacked computers; and the company goes after a whistleblower site that reveals its advice to those who want to subpoena personal information.

The network had been flooding the internet with spam, but a US judge cleared Microsoft's Digital Crime Unit to block the cyber criminals' command computers from the hundreds of thousands of machines worldwide that were infected with a Waledac virus.

Microsoft attorney Richard Boscovich said that the company decided the best tactic would be” to literally build a wall between the bot-herder, the command computer, and all of the other computers - effectively cutting the umbilical cord.”

Mr Boscovich, who works in the digital crime unit, said that it was of crucial importance that severing the connection between the bot herder and the bots was done in secrecy. As a result, Microsoft got a US judge to grant an ex parte temporary restraining order that let the firm erect the cyber blockade without warning bot-herders, masters of the 'botnet'.'

The judge was responding to a complaint drafted by Microsoft that argued damage to computer owners worldwide, and to the software firm, was major enough to warrant “this rather extraordinary order.”

Whistle that tune - not

Microsoft has managed to get part of the whistle blowing, government-document sharing site Cryptome shut down, says Wired Magazine.

Microsoft alleged copyright infringement on Cryptome’s proprietor after he posted a Microsoft surveillance compliance document that the company gives to law enforcement agents seeking information on Microsoft users.

As a result, Cryptome was shut down by Network Solutions and its domain name locked, closing a site that had been a thorn in government’s side since 1996. The site, which has since re-opened here, has posted thousands of documents that might otherwise never have been revealed.

The 22-page Microsoft PDF says that Xbox Live records every IP address you ever use to login and stores them for perpetuity.

According to the document, “If your investigation involves a stolen Xbox console, if the console serial number or Xbox LIVE user gamertag is provided and the console has been connected to the Internet, IP connection records may be available.”

Other info included in the document: Microsoft retains only the last 10 login records for Windows Live ID. As for your instant messages, it tells police that it keeps no record of what anyone says over Microsoft Messenger – though it will turn over who is on your buddy list.

And Microsoft has revealed its dragnet approach to privacy, offering some advice for potential subpoenaees looking for information from its social networking products:

“When you are looking for information on a specific incident like a photo posting or message posting, please request all group content and logs. We cannot retrieve single incident data.”