The Government has announced legislation which will lead to a huge expansion of surveillance powers of communications on the internet and mobile phones.
The Communications and Data Bill will allow the police and security services to keep track of who is calling who on mobile phones, the email addresses of all correspondents, and the personal IDs of people chatting on social networking sites.
The bill has already been attacked by privacy and civil liberty campaigners.
They have noted that its controversial publication comes on the day that much of the media is focussed on David Cameron's appearance at the Leveson Inquiry.
They also say that whistleblowers could be vulnerable to exposure, as a result of the proposed changes.
The new powers are seen by the Government, the police and the security services as essential to keep pace with innovations on the internet.
These have allowed organised criminals and terrorists to evade traditional methods of phone interception and monitoring.
Of the information that could be collected, Home Secretary Theresa May said that a quarter is being missed. She added that the situation is likely to get worse.
Communications Service Providers will have to store communications data, possibly to specially fitted "black boxes" - funded by the taxpayer.
The government said the cost of this would be £1.8bn over 10 years, but would lead to benefits of up to £6.5bn.
Mobile phone operators will also be expected to provide the duration of calls, the time of day they were made and the location of the caller to police.
No warrant would be required for these surveillance operations, which would need to be authorised by a "senior officer", Whitehall sources said.
"There would have to be a reasonable suspicion of criminal activity to trigger this sort of data collection," an official said.
"And there will be no collection of data in real time," the official added. Local authorities will be excluded from collecting data.
A warrant, issued by the Home Secretary, would be needed to access the content of communications.
Oversight of the surveillance is likely to be a major political issue. Britain is already the most snooped upon country in the world by Closed Circuit Televisions (CCTV).
The London borough of Wandsworth has more CCTV cameras than the cities of Johannesburg, Paris and Boston - combined, recent research has shown.
Officials said that judicial oversight of surveillance was not possible because "there simply aren't enough magistrates".
"If you are innocent then you have nothing to fear. Only criminals should fear this legislation," said Mrs May.
Civil liberties campaigners and many MPs are uncomfortable with the expanded powers.
In 2008, senior Conservative figures like David Davis and Liberal Democrats led by Chris Huhne successfully campaigned against the then Labour government's efforts to introduce a similar bill.
"This policy will track every email we send, every Facebook message and log every website we visit in a way that no other democratic country does," said Nick Pickles, director of Big Brother Watch.
"It is not for innocent people to justify why the Government should not spy on them.
"All we have heard from the Home Office is scaremongering and cheap rhetoric that has wholly failed to address the serious civil liberties concerns, feasibility questions or even say how much it will cost."
But Gary Beautridge, assistant chief constable of Kent and Essex police and director of the force's serious crime unit, said that criminals were rapidly opening the technology gap with police.
He said that many organised groups were communicating over the internet and the storage of data would accelerate investigations.
Mr Beautridge said that a recent successful prosecution on a paedophile convicted of 32 counts of abuse of children, including rape, would have been much quicker had the police been able to access his communications data which, under the new legislation, would be stored by a service provider.
"His last text was to another paedophile saying that he wanted to take and rape another child and eat it. I dread to think what could happen if we cannot move fast against these sorts of people," Mr Beautridge said.
Police say that 100% of terror cases, and 95% of organized crime cases, involve data collection.
Under the bill, data will be held for 12 months, with police given the opportunity to ask for an extension.