We have a lady of eighty living next door, a widow. She is a nice lady, but a few years ago she got a boyfriend just a couple of years older than her, who has moved in, but still keeps his own home.
At first he was OK, but then started getting more eccentric. We found out that he had entered our garden whilst we were on holiday to cut branches off her tree, which were interfering with their satelite signal.
In doing so, one of my hanging baskets was knocked down and destroyed, then disposed of, with no apology. We found out what had gone on from another neighbour who had seen him and then helped to move the large branches from our garden.
He created a large rubbish tip in her back garden. It got worse and worse and talking to them last year about it, he made it clear that he was not prepared to shift it. The whole patio was covered in a 3 foot high pile of garden rubbish, tree branches, plant pots, plastic bags from compost, carrier bags and other rubbish. They did not pay for a green bin, which is a chargeable service from the council in our area, so everything was dumped in the garden. We were increasingly worried about rats taking up residence, creating a threat to our own garden and property.
The matter was reported to environmental health and they were ordered to clear up the mess. The lady made him clear all the rubbish away, but blamed us for reporting it. At least they aren't noisy, I suppose it could be worse.