I called the police today about people sat in a car outside my house filling balloons with Nitrous Oxide and inhaling it. They've been doing this every night for about a week. They've been so noisy, which has been a pain as it's so hot we've needed the windows open at night. They were chucking the cannisters and balloons out of the car into the street today. At one point they drove off (very badly - really struggled to get around the bend in the road) then came back and did some more balloons. The police actually showed up and saw them shuffling the car back and forth (my neighbour has called multiple times with no response) but all they did was speak to them for about 30 seconds. Then the police drove off in one direction and the car drove off in the other. I know possession of NO is not illegal but driving under the influence definitely is. Anyone with police knowledge able to explain this to me?