Residents in Swansea who repeatedly put their rubbish out for collection too early face being fined up to £1,000.
Seven people have been fined so far
The city council is taking a tough stance on those whose bins are on the street before 1900BST prior to the day the dustbin lorry calls.
The authority says it is a major source of litter as often bin bags are ripped open by animals.
And litter is one of the main causes of complaints to the council.
Bags placed out early for collection are often torn by animals which results in the contents being strewn over the street
Swansea Council's David Jones
Seven people have already been fined between £75 and £100 and more than 300 have been served notices warning them to clean up their act.
The council's cabinet member for environment David Jones said: "We have identified refuse bags being placed out by residents well before the due collection day as a major source of litter within Swansea.
"The council requests that waste is placed out no earlier than the evening before the due day of collection in a bid to reduce littering problems.
"The council has started serving legal notices on residents who place their waste out, sometimes, days before collection is due.
"Residents who continually ignore this advice may also risk prosecution.
"Bags placed out early for collection are often torn by animals which results in the contents being strewn over the street."