Figures from the Attorney-General's department reveal Wyndham is the only Victorian council that has been snooping on personal data, seizing residents' information 31 times during 2010-11 and 2011-12.

The council's acting chief executive Kelly Grigsby said there had been another 18 authorisations in the past 12 months to chase people for unauthorised advertising, unregistered pets and illegal littering.

University of New South Wales Cyberspace Law and Policy Centre director David Vaile said non-police bodies such as councils should not be permitted invasive powers for pursuing such ''minor'' matters.

He said Wyndham's access to data showed legislation had been ''cast far too broadly'' and warned government surveillance was becoming more common.

Telecommunications data, often described as ''metadata'', includes the names and addresses of users and lists of their calls, text messages and emails. It also includes users' locations at the time they make a call. The content of messages, emails and calls cannot be accessed.

Mr Vaile, who is vice-chairman of the Australian Privacy Foundation, said revelations that Wyndham council was seizing residents' personal metadata were a ''warning sign'' of a slippery slope away from the values of an open and democratic society.

Ms Grigsby defended the council's actions, saying metadata was only accessed in a small number of cases where the information was deemed to be essential. She said ratepayers expected the council to take appropriate action against anyone who broke the city's laws.

''Retrieving a telephone subscriber's name and address for an investigation into an offence is an important tool.''

But Werribee's Michael Young said the council had overstepped the mark. ''Council does a lot of great things for the community but this is going too far,'' he said. ''Get your nose out of our private business.''

Wyndham Weekly