Anonymous for reasons. UK answer.

We lived in a semi-detached house next to a neighbour from hell for many, many years. We couldn't afford to move anywhere else. We shared a wall with her, and she would pound on it day and night and scream the most foul-mouthed abuse at us for no reason. She did have mental health issues, but they didn't stop her doing things she enjoyed, including shopping and socialising. Other people in the neighbourhood often called the police out to her because she was so abusive and threatening, but we never did for fear of making matters worse.

She had a violent adult son who lived with her, and neither of them were ever employed. They lived on benefits, and never bothered to look for work. The son eventually moved his girlfriend in.

We found out (from the neighbour herself) that between the three of them they were claiming for all kinds of benefits they were not entitled to, and were not declaring money they had stashed away. They had both tried to get themselves declared unfit for work on medical grounds, but had never succeeded, despite repeated attempts. The son apparently claimed on his forms that he was virtually confined to a wheelchair, even though he went to the gym and lifted weights every day.

In the end I anonymously reported them to the Department of Work and Pensions.

About six weeks later, they were called into the local Job Centre to be interviewed. It took a while, but eventually they all went to court, and were all found guilty of benefit fraud.

If they ever suspected it was me who reported them, there was never any sign of it. Eventually we inherited some money from a deceased relative and moved house. Happiest day of my life.