Lord Macdonald said: "Some of the offences that have been committed are exceptionally serious and they require grave punishment, and the sentencing guidelines cater for this. But we are also seeing exceptional punishment for opportunistic offences that appear, on the face of it, to be less serious. Coupled with the threat to remove benefits and to evict the families of rioters from their homes, we are seeing a response that risks becoming excessive and contrary to the norms of justice.