Uhh, the kid is AUTISTIC, not a brat. From the description he sounds like my neighbor’s son who is severely autistic and unable to care for himself. Sounds like the neighbor advocates the Nazi solution for undesirables.
I know I know... it is a bad situation and I think the kids parents are the ones at fault.
Imagine a new family moves in next door to you and their kid starts making bellowing noises all day every day- the lives of everyone in the neighborhood would be ruined.
The parents should not have allowed him to do this to everyone in the neighborhood. If he is that bad, maybe he needs to be medicated or institutionalized.
The person who wrote the letter took it too far, but I can clearly understand their feelings
I had a neighbor from hell once- so I am grumpy about the topic