Ai Wei Wei: "Self-censorship is insulting to the self. Timidity is a hopeless way forward."

Sometimes you see something that makes almost everything else seem a bit lame in comparison. The Ai Wei Wei exhibition at the Royal Academy  for example.

Ai Wei Wei fills eleven rooms in the exhibition and he hits all the high notes; surveillance, control, censorship, development and destruction, corruption, family, and justice.

Different materials are used, family history is invoked, social media is exploited and the work is both accessible and aggressive. It's not half-hearted. It hits its targets and it does have targets.

And in amongst it all there are some works that bring tears to your eyes. The first is Straight. This is a room filled with 96 tons of straightened rebars - these are the bars that are put into concrete and tied at both ends to add stability and strength to a concrete beam and so to a building.

And if you don't bother to tie the rebars off at the end, if you don't attach the ends of the rebars (and so the concrete beam) to a wall or another beam, they don't add strength to a building. The building becomes liable to collapse

So that's why so many buildings collapsed when there was an earthquake in 2008 in Sichuan Province. The most tragic thing is the buildings that were most likely to collapse were school buildings. In Sichuan school buildings the rebars weren't tied, the concrete used was substandard. Corners had been cut, standards dropped, money had gone into the pockets of corrupt provincial and party officials.

Children died because of it, almost ten thousand of them. That's the effect of corruption and greed. It's not a zero sum game. People die because of it.

That is what Straight is about. You go into the room, and there's a crowd of people standing around a television watching a twenty minute film showing the destruction, the bodies, the abandoned school backpacks (which made another Ai installation), the venal officials, the sobbing parents, and the appalling construction.

Then there's the work taken to reclaim the bent rebars (if they had been properly tied they would have snapped - the fact that they were bent is indicative of the corrupt building standards) and the banging of them back into shape. It's the documentation of an artwork that has its roots in the most tragic form of reality. It doesn't get more real than this. It's documentary art.

That was the film, which everybody who was there watched. There were some pictures of the ruins. There was the mass of rebars. And there on the walls are the names of those who died (Ai's team collected over 5,000 names. He was brutally beaten by police when these names were first published in China). For these dead children, the straightened bars are a memorial formed from the sweat of Ai Wei Wei's bar-straightening workers. For the provincial officials who traded the lives of children for  a new apartment or a designer watch, they are an accusation.

The other great work was SACRED. This detailed Ai Wei Wei's arrest and disappearnce for 81 days as he was held incommunicado by the Chinese state. He was imprisoned, interrogated, and watched in intimate detail, two guards standing over him for all this time without a break - when he ate, when he slept, when he showered, when he went to the bathroom. The guards would always be there.

So you go in the room, and there are 6 rusted metal containers. There are peep holes at the end, and peep holes on the top. Look in the peep holes and it's a diorama of Ai Wei Wei's imprisonment. You're made to work a little for your view - and it is quite shocking to always have these guards standing over their prisoner, who is rendered in very lifelike detail.

On the wall, there is Ai Wei Wei Twitter/Surveillance wallpaper. You're encouraged to photograph, to use social media, to tweet and facebook and Snapchat. Because for Ai Wei Wei that has made a difference (both in the past and right now). In that regard, it puts some other exhibitions to shame. No photography - and so no social media! Really? What exactly are you afraid of?

The exhibition is an art exhibition, and so it's about communication, and part of that communication is about using emotion, injustice, and striving for change to reach as many people as possible. It's activism on a grand scale, that works in the most direct and accessible way possible. There is anger in there, a sense of Ai Wei Wei  (and others - this is not a lone exercise) standing up for what he believes in. And he has suffered for it, so there's braveness in there, along with a healthy dose of aggression.

It's an example of what art can be. No bullshit, no compromise, no self-censorship. It's an example to us all.

Welcome to Pennsylvania: Jailed for Myspace

Continuing on the prison theme, this story was in the Guardian at the weekend. How corrupt, how venal, how greedy and destructive is it possible to be. This judge from Pennsylvania is hard to beat, but how many other low-lives are there in law, business, government, religion who are waiting to be unearthed.

Jailed for a MySpace parody, the student who exposed America's cash for kids scandal

Hillary Transue was 14 when she carried out her prank. She built a hoax MySpace page in which she posed as the vice-principal of her school, poking fun at her strictness. At the bottom of the page she added a disclaimer just to make sure everyone knew it was a joke. "When you find this I hope you have a sense of humour," she wrote.

Humour is not in abundance, it seems, in Luzerne County, northern Pennsylvania. In January 2007 Transue was charged with harassment. She was called before the juvenile court in Wilkes-Barre, an old coal town about 20 miles from her home.

Less than a minute into the hearing the gavel came down. "Adjudicated delinquent!" the judge proclaimed, and sentenced her to three months in a juvenile detention centre. Hillary, who hadn't even presented her side of the story, was handcuffed and led away. But her mother, Laurene, protested to the local law centre, setting in train a process that would uncover one of the most egregious violations of children's rights in US legal history.

Last month the judge involved, Mark Ciavarella, and the presiding judge of the juvenile court, Michael Conahan, pleaded guilty to having accepted $2.6m (£1.8m) from the co-owner and builder of a private detention centre where children aged from 10 to 17 were locked up.

The cases of up to 2,000 children put into custody by Ciavarella over the past seven years - including that of Transue - are now being reviewed in a billowing scandal dubbed "kids for cash". The alleged racket has raised questions about the cosy ties between the courts and private contractors, and about the harsh treatment meted out to adolescents.

Alerted by Laurene Transue, the Juvenile Law Centre in Wilkes-Barre began to uncover scores of cases in which teenagers had been summarily sent to custody by Ciavarella, dating as far back as 1999. One child was detained for stealing a $4 jar of nutmeg, another for throwing a sandal at her mother, a third aged 14 was held for six months for slapping a friend at school.

Half of all the children who came before Ciavarella had no legal representation, despite it being a right under state law. The Juvenile Law Centre has issued a class action against the two judges and other implicated parties in which it seeks compensation for more than 80 children who it claims were victims of injustice.

The prosecution charge sheet alleges that from about June 2000 to January 2007 Ciavarella entered into an "understanding" with Conahan to concoct a scheme to enrich themselves. The two judges conspired to strip the local state detention centre of funding, diverting the money to a private company called PA Child Care which it helped to build a new facility in the area.

In January 2002, prosecutors allege, Conahan signed a "placement guarantee agreement" with the firm to send teenagers into their custody. Enough children would be detained to ensure the firm received more than $1m a year in public money. In late 2004 a long-term deal was secured with PACC worth about $58m.

In return, the prosecutors allege, the judges received at least $2.6m in kickbacks. They bought a condominium in Florida with the proceeds. PACC's then owner, Bob Powell, who has not been charged, used to moor his yacht at a nearby marina. He called the boat "Reel Justice".

For a man who has agreed to serve more than seven years in jail as part of a plea bargain, Ciavarella comes across as remarkably unflustered. He invited the Guardian into his Wilkes-Barre home where he remains free on bail pending sentencing.

Though he pleaded guilty to conflict of interest and evasion of taxes, he insists that he took the money in all innocence, assuming it to be a legitimate "finder's fee" from the private company for help in building the detention centre. He denies sending children to custody in return for kickbacks. "Cash for kids? It never happened. People have jumped to conclusions - I didn't do any of these things."

He says that he regarded his court as a place of treatment for troubled adolescents, not of punishment. "I wanted these children to avoid becoming statistics in an adult world. That's all it was, trying to help these kids straighten out their lives."

As evidence, Ciavarella claims the percentage of children he sentenced to custodial placements remained steady from 1996, when he was appointed to the court, until he stood down from it in 2008. Yet the facts suggest otherwise.

For the first two years of his term his rate of custodial sentencing was static at 4.5% of cases. In 1999 - shortly before he allegedly began the racket with Conahan, according to prosecutors - it suddenly shot up to 13.7%. By 2004 it had risen to up to 26% of all teenagers entering his court.

Ciavarella hopes that with good behaviour he may spend only six years in jail.

Hillary Transue, meanwhile, is now 17 and in high school. She spent a month in detention for the parody. For many months afterwards she was ostracised by friends and neighbours, labelled a delinquent.

"It's nice to see him on the other side of the bench," she says of Ciavarella. "I'm sure he understands now how it feels."