Interesting thread 
I have new neighbors next door, and well, it's like this. A woman, husband and a little girl (about 5 I'd guess). Anytime I meet the woman she's lovely, smiley, friendly. She likes animals. I like her. Then at nights she - obviously drunk - keeps shouting to her child, to her husband. Telling her husband she's the one to make money and insulting him and putting him down. Telling her daughter she will give her up on adoption, I know she hits her too. I hear the gild cry every day, either about something serious or about any silly thing (they won't take her to the movies or whatever), because with all that she'd obviously becoming hysterical.
This many times late at night, up to 2, 3 am. They're also often out on the backyard late at night drinking and talking and laughing loud, on weekdays.
Sigh.
That's horrible, and as a neighbor you're powerless.
I feel sorry for all of them, but especially the child. The adults can change their situation, but the child has no options.
That's so sad.