Experian has reported that 12 million pieces of personal information were traded by fraudsters between January and April this year.
The report, which focuses on online retail crime, shows that online information theft has risen threefold since 2010, and many consumers are unaware at first that their identity has been stolen.
The average consumer has an around 26 separate logins online, but only five different passwords. Once one account is hacked, this makes it much easier for fraudsters to log in to other accounts that the victim owns.
Experian advises people to change their passwords regularly to avoid becoming a victim of internet fraud.
The research also found that two thirds of people have active accounts that they no longer use, leaving them vulnerable.
The survey revealed that the police find it difficult to deal with online retail crime with 57 per cent of companies saying that they had reported frauds to the police but 53 per cent encountered a lack of interest.
Only nine per cent of frauds reported by online retailers to the police resulted in prosecution.
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