It seems like Facebook neighborhood groups are just the modern form of the gossipy people who sit at home all day watching the street with nothing to do.
Typical posts for our neighborhood are:
“Does anybody know who cut down that tree?”
“I saw a gray cat by the grocery store. Did someone lose a cat?”
“There was a suspicious looking guy by the laundry room this morning. He didn’t do or say anything, but everyone should watch out!”