Imprisonment punishes offenders' families  Even though liberal democratic systems of justice continue to place an emphasis on punishment rather than rehabilitation, sentences are still required to be proportionate to the crime that they punish. Further, a sentence must only punish those judged responsible for the crime. Collective punishment and guilt by association are not tolerated within rational, liberal systems of criminal law.  Imprisoning or fining an offender often places an intolerable burden on the offender's family. If the offender is a breadwinner, the family is denied the income that he would otherwise provide. They may be forced to use inadequate benefit systems. Other members of the family may be forced to take up a second job, adversely affecting childcare arrangements. Any fines that an offender is ordered to pay are often impact upon his family, damaging household budgets and forcing other family members into debt.  The negative effects of a custodial sentence extend beyond the offender himself. Financial and social deprivation may have a minimal impact on an offender while his is imprisoned, but may cause considerable suffering within his family. Sudden social isolation and poverty have themselves been shown to provoke criminality and increase childhood deviance.  Corporal sentences allow a punishment to be targeted only at the criminal, not at their families.