The identification and location of computer criminals can be extremely difficult. Today, a single communication may be routed through a U.S. cable company or ISP, across the Atlantic via satellite, and across Europe via a wireless phone network. A trace of such a communication will require the cooperation of numerous domestic and foreign telecommunication companies and law enforcement agencies. Differing legal regimes complicate the issue. In some countries, for example, ISPs and other telecommunications companies are required by law to destroy transactional data -- data that may be crucial to the identification and location of a cybercriminal.