The authorities in the United States say they have dismantled four big networks selling illegal date-rape drugs over the internet across the whole of North America.

Law enforcement will pierce the cloak of secrecy surrounding e-drug traffickers and bring them to justice

Drug Enforcement Agency head

They said a sweep across 84 cities had ended in more than 100 arrests - and the seizure of enough chemicals to make 25 million doses of a drug frequently used by rapists to subdue their victims.

Customs and FBI officers joined local and federal police in co-ordinating the raids, the first of their kind.

Centres of operation

Festus, Missouri Sparta, Tennessee Quebec City, Canada Detroit - San Diego

The main drug targeted was GHB, or Gamma Hydroxybutyrate - an odourless and colourless liquid often slipped into a woman's drink, causing loss of consciousness and usually leaving the victim with little or no memory of any sexual attack.

Attorney General John Ashcroft described the raids as "a dose of harsh reality for drug traffickers who seek to exploit the vast markets and anonymity of cyberspace".

"Law enforcement will pierce the cloak of secrecy surrounding e-drug traffickers and bring them to justice," said Drug Enforcement Administration Director Asa Hutchinson.

Fast spread

Operation Webslinger took place on Wednesday and Thursday, though the investigation began two years ago.

GHB facts

Used as an anaesthetic in World War I Users may suffer sickness, stiff muscles, fits or comas Concerns have grown that sex attackers use the drug to sedate victims

Dealers found customers via websites and personal email accounts, disguising their products as inkjet printing supplies and cleaning solutions.

News about the websites spread fast, especially among teenagers and young people.

GHB is also known as "liquid ecstasy" and is passed around at night clubs. It can be fatal when taken with alcohol.

However, it is also promoted as an alternative to alcohol, giving the same effect as several drinks but not showing up in a breathalyser test.