One of the first loan sharks prosecuted under new laws to curb illegal money lending has been remanded in custody to await sentence later this month.
The 39-year-old man, who cannot be named by legal order, was described at Luton Crown Court as "Fagin-like".
Lawyers said he instilled fear among the vulnerable people he exploited in his home town of Dunstable.
Police said his deals financed a life of luxury and expensive cars while he claimed benefits for over 10 years.
Detectives believe he made more than £250,000 between May 2003 and January 2004, without paying income tax.
Many of his victims were single parents and drug addicts desperate for cash and already in debt.
'Manipulative and violent'
He forced them to hand over benefit books as security for loans and he took them to post offices to collect payments which he would then snatch.
The court was told others were even sent out to commit robberies to pay back the money they owed.
He was a "manipulative and violent" person, the court heard.
His interest rate was 50% over two weeks, meaning a £100 loan paid back over a year would cost the borrower £1,300.
Police raided his home and found £12,000 in cash in a safe.
The defendant was found guilty of conspiracy to convert criminal property, engaging in activities requiring a Consumer Credit Act licence, possession of criminal property and conspiracy to handle stolen goods.
He was remanded in custody by Judge John Bevan QC and will be sentenced later this month.
He may also face proceedings under the Act to confiscate money and property allegedly bought with the illegal proceeds.