Prior to the passage of the Police and Criminal Evidence Act in 1984, the supply of information from banks to the police was conducted on a wholly ad hoc basis, sanctioned by law only following the laying of criminal charges. In a 6-year period, the United Kingdom has moved from a legal position in which bank account details could be revealed only after the account holders had been charged to one in which routine interchanges, court-authorized or not, occur between banks and a plethora of police and regulatory agencies. The war on drugs assumes primary responsibility for this change as it is the one crime issue on whose seriousness most nations concur. Finally, the article considers likely future trends in controls over money laundering and concludes that the effect of the various legal and practical cooperation measures on levels of criminality and on the organization of crime remains unclear. 23 references (Author abstract modified)