You can call the police. If not for the noise, then a simple crime as littering. After all, they are throwing diapers on the ground.
You could also call the Health Department. Used diapers are a health hazard, as kids may play in them. They also draw rats, which is another health concern.
You could make an anonymous call to the I.R.S. - report them for tax evasion. If they're on aid, you could call the aid department and report them for working and collecting aid.
Or, you could take shit and smear it on their door handles, as one posted reply did.
I would not talk to them at all. I wouldn't let them use my car, even if they're bleeding to death. There are ways to fuck with them, just use your head & don't get caught. You'd be the one going to jail.
It seems that people like them are going to get themselves evicted sooner or later just by virtue of not paying their rent or bills on time. Perhaps anonymously leave rental ads for them that shows cheaper places to rent. Maybe they'll make some phone calls and get out.
I MOVED TO HACKNEY ABOUT 7 YEARS AGO THE NEIGHBOUR NEXT DOOR IS YES A EUNICH AND A VERY POWERFUL CROOK AND DRUG DEALER AFTER FEW ARGUMENTS I WAS TAKEN TO COURT WITH ONE WORD OF SLANDER AND ON TOP 50 THOUSAND LIES THAT I DAMAGED HIS/HER CAR ME A RICH WOMAN EXCUSE ME. AFTER THAT I GOT DOG TINS INTO MY GARDEN AND OTHER TRASH EVERY DAY IT BEGAN TO PILE UP WHEN I GOT FED UP I THREW IT BACK INTO HER/HIS GARDEN AND YOU CAN GUESS IT WAS TRICK SHE/HE HAD GOT A FLOODLIGHT CCTV AND WITH ME THROWING HIS/HER OWN TRASH AND ON TOP MAKING UP ANOTHER 50 THOUSAND STORIES THIS CROOK HAD ME ARRESTED THIS DOES NOT STOP THEN THREW BLEACH AT ME WHICH WAS WITNESSED BY A FRIEND THEN ON TOP OF THIS DAILY RINGING THE POLICE AND NOISE POLLUTION AND RINGING PEOPLE ALL DAY COMPLAINING MOANING TO COUNCIL AND HOUSING ASSOCIATION THAT I AM MENTALLY ILL AND SHOULD BE SECTIONED AND HE/SHE MAKES HER OWN DIAGNOSIS OF ME.
ALSO KEEPS ON SAYING TO ONE AND ALL HER/HIS LIFE IS HELL BUT WHEN THE OFFER OF A TRANSFER IS GIVEN NO HE/SHE DOES NOT WANT TO MOVE.
YOU GET IT IT IS ALL A BIG DRAMA HAVE ANYONE GOT A NEIGHBOUR FROM HELL THAT IS WORSE THEN THIS?