Yep, when we first moved in here, the neighbours made it abundantly clear how unhappy they were at the influx of cats!(I had four, then five, then four again sadly.)
The main problem was that the man is a keen gardener and cats (not necessarily mine) were messing on his garden. I posted him a CPL "cats and the law" brochure through his letterbox and he was also bought some repellent pellets that were non harmful and were meant to deter cats.
Gradually, despite not being especially happy about the cats, he and his wife have come to accept them. To my knowledge, though, they never threw heavy objects at my cats to deter them from their property. It's definately worth trying the reasonable approach first, and then if behave unreasonably you'll have the upper hand, so to speak.