Yup. I was in the grocery store tonight with my husband, and some woman had her ~4 year old girl with her. The girl was shrieking - not yelling, but the ear-piercing, make-dogs-howl high pitched shrieking - to get attention. She would shriek every 15 seconds or less, and this went on for a few minutes while I looked for a particular roast cut that I needed, then asked the butcher if they had any, and then tried to figure out what cut of roast I needed to substitute. The mom shushed her kid only twice, and only distractedly, as she was chatting and thus busy, apparently. Meanwhile my husband and I moved a few aisles away so his ears could stop ringing - and literally, they were - and I could concentrate to look it up online. This only reinforces my belief that some parents tune their kids out pretty effortlessly and don’t realize the level of volume they can produce.
I live across the street from a grade school, where they have outdoor recess in decent weather. I know that little kids make noise, but these kids only (extremely rarely) shriek. I suspect the teacher monitoring their play keeps them in line if they haven’t already learned when shrieking is OK. They do yell. Yelling in play is fine; shrieking makes me tense, and then makes me want to try to ignore the kids as much as possible if it continues. This is a dangerous precedent, as some honest shrieks of fear or pain may be ignored due to too much wolf-crying.
And yeah, the neighbors are probably just being douches, but still. Shrieking = bad.