According to a report by the UK Information Commission, a "horrifying" number of firms, government bodies and other public agencies have breached rules designed to govern the use of personal information.
The UK Information Commissoner, Richard Thomas said firms had a responsibility to ensure that they were more careful with customer and client data. Three of biggest firm to be publicly named include Orange, Barclays and NatWest.
The Ministry of Justice has warned that in the future, those misusing personal data could be given prison sentences.
According to the BBC: "Mr Thomas received nearly 24,000 enquiries and complaints about personal information issues in 2006-07.
His report said 56.5 per cent of these required only advice and guidance, while a breach was likely to have happened in 35 per cent of cases, of which a further 77 per cent resulted in remedial action."
According to Thomas, 13 per cent of complaints where about internet firms.
"Frankly these are inexcusable. None of this is really rocket science - security is fundamental," he told BBC Radio 4's Today programme.