Yes, debit cards make our streets safer. But they make the Internet more dangerous.

Cash means crime. It's as attractive to street thugs as it is to Bond villains. You can spend it anywhere, on anything, and it's almost completely anonymous. Scientists have long suspected that reducing the role of cash in American society might reduce the incidence of physical crime. A new economic study shows switching people from paper welfare checks to electronic debit cards is linked to a drop in assaults, burglaries and robberies. The findings suggest a cashless society would indeed be a more peaceful one. But even as fewer people use cash for everyday transactions, that creates opportunities for new kinds of theft that involve very different players, wielding a very different playbook. The question now isn't whether electronic payment methods reduce crime. It's whether they're changing the criminal landscape in a way that reduces some crimes and facilitates others. Instead of assault and burglary, we're seeing a rise in malware and botnets.