Sensitive personal information has been lost or stolen from councils in thousands of cases, research says.
Local authorities recorded 4,236 data breaches during a three-year period from April 2011, a study by privacy campaign group Big Brother Watch says.
Its director Emma Carr said this showed "shockingly lax attitudes to protecting confidential information".
The Local Government Association said breaches are "proportionately rare" given the volume of data handled, though it noted that compliance with security controls must be improved.
Ms Carr said: "Despite local councils being trusted with increasing amounts of our personal data, this report highlights that they are simply not able to say it is safe with them.
"A number of examples show shockingly lax attitudes to protecting confidential information. For so many children and young people to have had their personal information compromised is deeply disturbing.
"With only a tiny fraction of staff being disciplined or dismissed, this raises the question of how seriously local councils take protecting the privacy of the public."
"When [breaches] do occur, robust investigations and reviews are immediately undertaken to ensure processes are tightened."
You can read the full article on BBC News here.