If we wanted a masterclass in the degradation of the human species, this week we got it. It was on BBC1. It was on Monday night. It wasn't a programme about the massacre in Srebenica. It wasn't a programme about gang rapes in the Congo, or the shooting down of peaceful protesters in Homs. It was a programme about a care home for adults with learning difficulties in Bristol.

The residents of the care home, according to the programme, spend quite a lot of time lying on sofas. They also spend quite a lot of time lying on the ground. But when they're lying on the ground, they don't look very relaxed. They don't look very relaxed, because sometimes they've got an arm around their throat. Sometimes, they've got someone kneeling over their neck. Sometimes, they've got a blanket over their face, or a chair over their chest.

Sometimes, they've got someone poking them in the eye. Sometimes they've got someone bouncing on their lap. Sometimes, they've got someone hitting them in the face. Sometimes, they've got someone kicking them in the back. Sometimes, they're shaking. Or twitching. Or screaming out for help. Sometimes, the word they're screaming out is "Mum!"

But there isn't any point in screaming out the word "Mum!" because their mum isn't there, and because the people who are kneeling on their neck, or hitting them in the face, or poking them in the eye, are the people who are looking after them. The people who are looking after them are called Wayne, and Alli, and Charlotte, and Graham. And Wayne, and Alli ,and Charlotte, and Graham, don't like it if the people they're looking after scream out "Mum!". Wayne, and Alli, and Charlotte, and Graham, say things like "do you want me to get a cheese grater and grate your face off?", and "I am going to bite your face off" and "when you hit the floor, do you reckon you'll make a thud or a splat?"

Wayne, and Alli, and Charlotte, and Graham, get quite bored. So, sometimes they play games with the people they're looking after. Sometimes, they take away the thing that the person they're looking after cares about most. Sometimes, they drag them out of bed, and throw them on the floor, and then watch them try to jump out of the window.

Sometimes, they take them to the shower, while they've still got all their clothes on, and blast them with cold water. Sometimes, they throw mouth wash over their face, and squeeze toothpaste over their clothes, and leave them to get cold. Sometimes, they decide that they're not cold enough, so they take them outside, where it's really cold, and then watch them shiver and shake.

Sometimes, if they want to make their games more fun, they can say things like "nein, nein, nein!" and pretend they're Nazi officers. If they knew other words in German, then they'd be able to say them, too. But they don't really need to know other words in German. They can say some quite poetic things in English. They can, for example, say things like "suffocate on your own fat!" and "I expect he'll soon be kissing the carpet". But they can also say things that aren't very poetic. They can say things like "Don't push it, or I'll put your head down the toilet." And then they can take them to the toilet to teach them a lesson.

The lesson, it's true, isn't all that clear. It might be that you should be very careful not to be born with any kind of learning difficulty, because if you are, this may be what you get. It might be that you should be very careful not to be the parent, or brother, or sister, or friend, of anyone with a learning difficulty, because this is what the person you love might get. And it might be that this is how healthy, well-fed (and, judging from the programme, sometimes very, very well-fed) people with steady jobs, working in a bright, new building, sometimes decide to pass the time.

It's quite hard to see how Wayne, and Alli, and Charlotte, and Graham, thought that this was a nice way to pass the time. It's quite hard to see how Appoo, who's a qualified nurse with 35 years' experience, could think that watching a woman with a mental age of five being hit by her carers was such a nice way to pass the time that it made him smile. But lots of people, in lots of places, think that doing things like this is a nice way to pass the time. In prisons, in police stations, in detention centres, in refugee camps, in care homes, in hospitals, and in offices, a bully gets some power. And other people, who are afraid of the bully, start copying the bully. Sometimes, the bully is just horrible, but sometimes the bully is violent, and sometimes the bully thinks that being violent is such good fun that he tries other things, too. Sometimes, he starts trying out different ways to torture someone, and the people around him start trying them out, too.

Wayne, and Alli, and Charlotte, and Graham, are not a few "bad apples". Winterbourne View care home, according to the film made by the Panorama reporter who smuggled hidden cameras in, seems to have had an awful lot of bad apples. So does Abu Ghraib. So does the secret police in Syria.

In most places where very bad things happen, most apples are bad. At Winterbourne View, there was a good one. He was a senior nurse. His name is Terry Bryan.

Terry Bryan complained about what was going on to the manager of the care home, who didn't reply, and to the manager's manager, who didn't reply, and to the Care Quality Commission, who didn't reply, and then again to the Care Quality Commission, who again didn't reply, and then again to the Care Quality Commission, who again didn't reply. And then he told Panorama. And then the manager, and the manager's manager, and the Care Quality Commission, and the parents of Simone, who was drenched in cold water and left to lie outside in the cold, and of Simon, who was punished for his bear hugs with a bear hug in the toilet, and of all the other patients who were kicked, and hit, and smashed to the floor, got to see how Wayne, and Alli, and Charlotte, and Graham, passed the time.

"The only thing necessary for the triumph of evil," said the philosopher Edmund Burke, "is for good men to do nothing". What he didn't say is that it takes quite a lot of courage to speak out.