.... you lived in a block of privately rented and owned flats, you shared a drive way and one day came home to find some chalk drawings on the floor from one of your neighbours kids? Some squiggles, a stick man and a name of one of the children?
Would you speak to the parent and tell them you don't like it and please could you stop?
Would you ignore it unless it kept happening and assume the parent had dealt with it?
Would you speak to the managing agent, get them to come round, take photos of the evidence and send it to all 16 flats telling telling them how this would not be tolerated?