A child can now be at greater risk sitting in a bedroom on a computer than outside the school gates, the Home Secretary said today.
Theresa May said cyber-crime was a serious problem which caused more losses than burglars stealing televisions and DVDs from homes.
The new National Crime Agency (NCA) would help tackle this and make people "feel safer", she said.
In a key speech on police reform in central London, Mrs May outlined plans to give communities tougher protection from anti-social behaviour to put an end to the "horror stories" of victims being ignored despite making repeated complaints to the authorities about problem neighbours.
It comes after HM Inspectorate of Constabulary (HMIC) said last week that only a low number of crimes were recorded from anti-social behaviour cases and the identification of repeat, vulnerable and intimidated victims was "poor" at the first point of contact.
Mrs May said: "As well as growing, the threat from organised crime is also changing.
"Increasingly, the biggest criminal losses do not come from the burglar who breaks into houses to steal TVs or DVD players, but from the cyber criminal who raids bank accounts directly.
"A child can now be at greater risk sat in their bedroom on their computer than they are outside the school gates.
"And given the nature of the criminal threat, it is now no longer possible to keep communities safe through good local policing alone.
"Highly visible neighbourhood policing is vital, but it won't deal with cyber crime.
"Arresting drug dealers is important, but it won't stop the flow of drugs from overseas."
She went on: "That's why we need a powerful new crime-fighting force that works across different police forces and agencies, defending our borders, coordinating action on economic crime, protecting children and vulnerable people, and active in cyber space.
"That body will be the National Crime Agency."
Outlining pilot schemes to tackle repeat incidents of anti-social behaviour, Mrs May said: "It's too easy to overlook the harm that persistent anti-social behaviour causes.
"Many police forces, councils and housing providers are working hard, but I still hear horror stories of victims reporting the same problem over and over again, and getting no response.
"Just last week I met a woman who had been telling the police about anti-social behaviour in her area for over two years - and it's still going on.
"These long-running problems - and the sense of helplessness that goes with them - can destroy a victim's quality of life and shatter a community's trust in the police.
"That's why we proposed a 'community trigger' as part of our reforms to anti-social behaviour laws.
"The trigger will give victims and communities the right to demand that agencies who had ignored a problem must take action.
"So we are now working with a number of local authorities to test the community trigger on the ground and pilots will begin by the summer."