The investigators had a hard time understanding what happened to the money due to the complexity of the network, so they asked for help. But in order to answer their questions, we had to obtain the bank statements from more than a thousand bank accounts at dozens of different banks, including all transactions from the last five years. We requested this data from the corresponding banks in a machine-readable format and loaded it into an Oracle database. However, we quickly discovered that there were missing observations in the data. Sometimes, there would be months or even years missing. In many cases, the employees from the bank had simply pressed the export button on their software, not knowing that data older than two years is automatically moved to an archive database and not included in the export. In other cases, the export skipped entire months for some unknown reason.