| It is as reasonable as proactively detaining everyone using tatoos or sports clothing. Correlation does not imply causation. Ethically, I do not think it is correct to outright flag an entire country. It can be used as one factor, but that in itself is not enough. Japan for example, a country that is not usually associated with crime, has one of the most profitable crime organizations in the world, the Yakuza. The UK might be where most transactions tied to money laundering are conducted, and so on so forth. In the grand scale of things, Nigerians are in a lower order of magnitude when it comes to dirty money. Fraud detection, at scale, takes not one or two but many factors in consideration. That would produce a level of confidence that will translate into a suggested action. If the confidence is high, a fraud detection system will take an action without human intervention. If the confidence is low, a human needs to intervene and take action. |
For example, you speak of "presumption of innocence" and "burden of proof" as "core concepts of our justice system". These are only core concepts of our criminal justice system; our civil justice system has very different rules for burden of proof, for example.
Some countries have much, much higher percentage of fraudulent transactions than other countries, and it's perfectly reasonable for Western Union to use country of origin as a factor in raising the fraud red flag. Western Union doesn't have the power to arrest anybody, and they have no reason to "presume innocence" for any one of their customers. If anything, when it comes to monetary transfers, I think it's safer to "presume guilt", that is assume all transactions have reason to be fraudulent, and then only let transactions through if you have strong reason to believe they are not fraudulent.