The Department of Education was among the bodies criticised for misuse of personal information taken from databases last year, according to the Data Protection Commissioner's annual report.
The commissioner, Mr Joe Meade, published some of the "lowlights" of the year 2000 in the document, which was published yesterday.
Mr Meade said there had been a significant increase in the number of complaints made to his office by members of the public last year.
The number of formal complaints in 2000 was 131, compared with 105 in 1999.
Most complaints involved organisations in the telecommunications and IT sectors, financial institutions, direct marketing companies and public services.
The number of inquiries rose from 2,200 in 1999 to over 3,100 last year.
These queries concerned credit ratings, direct marketing and access requests.
The commissioner said the increases reflected the Irish public's growing concern about the security of data.
He said people were worried by the amount of personal information that State and other institutions might hold about them on computer.
People were increasingly bombarded with unnecessary and annoying junk mail, "spam" e-mails and phone calls, he said.
They were also aware of possible surveying of their behaviour and lifestyles through monitoring of their activity on the Internet.
"Ordinary people are getting more concerned about the possibility of `Big Brother'. I look forward to assuring everybody that this office provides assurances when human rights are in danger," he said.
Mr Meade said the correct balance must be struck between organisations' operational requirements and a person's right to privacy.
The Data Protection Act, 1988, was enacted to deal with privacy issues arising from the increasing and complex amounts of information about individuals kept on computer systems.
The Act requires the commissioner to investigate complaints from individuals who feel their data protection rights have been infringed, and to issue a decision on such complaints. That decision is subject to a right of appeal by either party to the courts.
Mr Meade said those who drafted the Act could not have foreseen the scale of changes that had arisen in the past decade.
Mr Meade said data controllers in Ireland generally respected their obligations. However, he warned those who failed to comply with the law that he would not hesitate to use his powers to ensure the privacy rights of individuals were respected.
The commissioner said he welcomed the Government's REACH initiative, which aims to deliver public services electronically and share personal data within the State sector.
However, he stressed that participation in REACH should be voluntary and said irrelevant information should not be included on databases.
"No one should have their details loaded on the REACH database without their full and informed consent," he said.
