Unthinkable, surely, in late 20th-century Britain? Except when those concerned are paedophiles, perpetrators of crimes so repugnant that their convictions are never spent. Many of them have served their time, but cannot pay their debt to society and face a life as medieval outcasts.
Robert Oliver has been hounded out of five English towns since his release from prison, after serving eight years of a 15-year sentence for his part in the killing of 14-year-old Jason Swift. Now he has nowhere else to go and has surrendered himself at Brighton police station, television set under one arm and all his worldly possessions in a carrier bag.
The police don't know what to do with him. If he chooses to go out, all they can do is follow him around, make sure he doesn't go near any children and protect him from the lynch mob.
Now, The Independent is totally against lynch law and vigilantism. But we have to admit that, while we are not in the mob, we could be accused of inciting the crowd from the sidelines. We helped to expose the terrible crimes of child abusers in care homes. We campaigned to have the voices of the abused heard. And we lent our weight to the NSPCC's campaign for a national register of child sex offenders.
This is a field in which we are prepared to consider measures from which civil libertarians have traditionally shrunk. The register is a small step towards improving the exchange of information between agencies so needed to detect and prevent child abuse. Nor should we shrink from considering seriously more drastic measures, such as surgical or chemical castration or literal life sentences.
But it cannot be right that paedophiles are driven into a kind of subhuman limbo, hounded to death or despair in the gutter. Nor is a policy consisting entirely of negative sanctions likely to succeed.
It is time to stand back and examine the nature, extent and causes of sexual preoccupation with children. The first point to be made is that most abusers are related (or step-related) to the children they molest. Predatory, calculating strangers - the focus of most popular fears - are rare, although that is not to say we need not worry about them. Second, one of the main causes of child abuse is physical or sexual abuse in the offender's own childhood. Both points suggest that the best policy of prevention is to strengthen families and protect children. But even if Tony Blair's most ambitious rhetoric of "strong families" were to be realised, paedophiles would still exist and children would still need to be protected.
And this is the matter where the instincts, even of liberals, are their most draconian. Indeed, in principle, there is a strong case for castration - normally the first refuge of hangers, floggers and moral simpletons. A substantial proportion of paedophiles are unwilling or unable to change their behaviour. But the evidence is that it does not work. Neither surgical removal of the testes nor drugs completely suppresses the sex drive. Last year, a new law was brought in requiring second-time child sex offenders in California to choose one or the other: but since then the hanger-flogger lobby has been mysteriously quiet, suggesting, at the very least, an absence of instant results.
So the liberal orthodoxy must remain dominant. Offenders should be encouraged to take responsibility for their behaviour and helped to change it. Prison is not the best place to do this, nor is the exclusive company of other offenders the best environment - a serious policy of containment will be expensive. But it will require harsh measures too, for the few who will always be a threat. If medical intervention can be shown to work, it should be an option available. If some people have to be locked up for the whole of their lives, that should be, too. The important thing is that someone must decide.
The real question about Robert Oliver is whether or not he is a threat to child-ren. If he is, or if there is serious doubt, he should not have been let out (especially as there are seven years of his nominal sentence to run). If he is not, he should be protected. Someone must decide. Sex crimes against children cannot be treated as a single episode to be decided by a judge at one point in time, but a lifetime's responsibility for a clearly defined agency.