Residents in Darlington are being warned to shred personal information and delay putting out their bins after an increase in rubbish bag slashing.
Darlington Council said it was concerned as identity thieves often slashed bags to find personal information to commit fraud.
It said it was patrolling areas worst hit in an effort to catch those interfering with residents' waste.
It said two people had been prosecuted, receiving fines of more than £200 each.
To combat the problem, the council is asking residents to shred personal information and, where possible, not to put their rubbish out for collection until 0730 BST on the day of collection.
Bill Dixon, of Darlington Council, said: "Bag slashers are often looking for people's personal information which they can use fraudulently and they can make a real mess of our residential streets and back lanes.
"I would urge people to shred personal documents before they throw them away and ask people, if at all possible, not to put their rubbish out until 7.30am on the day of collection.
"As most bag slashing happens at night, this will help reduce the problem greatly."