Police in five counties in eastern England have joined forces to combat the problems of bogus callers and rogue traders.
Bus adverts ask: "Who is dad letting in today?"
Officers from Norfolk, Suffolk, Hertfordshire, Essex and Cambridgeshire were in Ipswich on Tuesday for the official launch of the month-long awareness-raising campaign.
The scheme is aimed particularly at younger people with elderly relatives who may be vulnerable to distraction burglars.
Police have designed a leaflet highlighting safety measures, and many buses are to carry advertisements warning of the dangers.
Inspector Dave Northcott of Essex Police said: "Distraction burglary and rogue trading, where inflated prices are charged for unnecessary work, cause misery to the victims.
"Elderly and vulnerable people tend to forget the advice given to them and we aim to increase awareness of this fact by the scheme."