I'm surprised no one has mentioned Josef Fritzl yet? The man imprisoned his own daughter in a dungeon he built specifically for her and raped her for 24 years, he burned her baby that died in an incinerator. I remember his mugshot gave me chills as a teenager, the man was a monster with no remorse.
But probably the WORST thing I have ever read (my eyes actually water every time I think about it) is a Japanese girl named Junko Furata. This girl was tortured for weeks by three boys in Japan, the stuff they did to her is unimaginable (dropped anvils on his stomach, cut her eyelids off, ripped bits of her off with pliers and much more). I would highly encourage you NOT to read any more about this because I thought my flatmate was exaggerating when he told me not to look it up, of course being an idiot, I looked it up. I've never felt so disturbed in my entire life. The worst thing is these three boys got away with it!! They got given new identities and they literally out there somewhere in Japan today. What the actual duck.
As for animal abuse stories in the news (like the lady putting the cat in the bin, I remember reading about people putting their kittens in microwaves and one lady put her kitten in a washing machine), I genuinely think people who abuse animals should be put in some kind of Hunger Games where they're all made to kill each other and then the winner gets killed anyway. I volunteer at the RSPCA and the state some cats come in is horrid. We had a kitten with chemical burns in the other month, and another cat came in because its owner was filmed mistreating it. I hate the human race sometimes.