The powers were used more than 750 times by councils in southern England
Councils in southern England have routinely used powers brought in to fight crime - including terrorism - to spy on people, the BBC has learned.
Figures obtained by BBC South show the Regulation of Investigatory Powers Act (Ripa) was used more than 750 times by the councils in 2007/08.
The figures relate to Hampshire and the Isle of Wight, Dorset, Berkshire, Oxfordshire, Wiltshire and West Sussex.
Overall, only one eighth of the council inquiries resulted in further action.
Under Ripa laws, councils can access phone and email records and use surveillance to detect or stop a criminal offence.
The BBC South investigation discovered councils in southern England had used Ripa to investigate matters including illegal taxis, dog fouling, child protection issues, benefit fraud, noise nuisance and planning enforcement.
Local Government Association chairman Sir Simon Milton said overzealous use of the powers could alienate the public.
He has written to councils warning them about using the powers for "trivial offences" such as dog fouling.
The figures reveal Gosport Borough Council used Ripa to investigate whether illegal clam pickers were operating.
West Berkshire used the powers 192 times - 24 cases resulted in further action with police, courts, or other agencies, although it is not known if any resulted in convictions.
The figures were all obtained under the Freedom of Information Act.
A Gosport Borough Council spokeswoman said Ripa had been used because "people were harvesting clams from an unclassified bed".
"This is illegal and if the clams had got into the food chain it could have proved potentially dangerous to the public, so officers decided that surveillance would be used to stop the practice.
"However the new council leadership has insisted the council will no longer use 'big brother' tactics in future."
She said Ripa would only be used for "really serious offences and only with prior member approval".
Meanwhile Poole Borough Council, which admitted in April it had spied on a family to see if they really did live in a school catchment area, said it was reviewing its use of the powers.
Tim Joyce and Jenny Paton were exonerated after surveillance
Tim Joyce and Jenny Paton and their children were put under surveillance by the council for more than two weeks without their knowledge.
Miss Paton described it as "hugely disproportionate". The couple were cleared of any wrongdoing.
At the time the council defended its actions, but on Monday a spokesperson said the use of such surveillance methods was "already scheduled to be reviewed by a council scrutiny committee in July".
The Information Commissioner's Office (ICO) has begun an investigation over the council's use of the powers, after expressing "concerns".
The council also admitted using the powers on a total of 17 separate occasions since 2005, including to make sure fisherman were not illegally gathering shellfish in Poole Harbour.