The most amazing pieces of federal software that I've seen are the sections of IRS forensic accounting systems that catch anomalies. (Not that the feds are known for programming prowess, but when it comes to taxes, they seem to take it more seriously.)
Credit providers run pretty sophisticated software, too. It's simultaneously looking for fraud, assessing customer risk in real time, trying to detect money laundering and terrorism financing, looking for indicators of tax evasion and a bunch of other things.
I remember being told years ago that tax department auditors could estimate income to within a few hundred dollars based on lifestyle alone. I expect that technology and powerful software makes that possible on a larger scale than ever before.
It's important for people to remember that as a general rule transactions of $10,000 and over are not illegal
per se. In the vast majority of cases they'll just be automatically reported and there'll be no further investigation unless some additional factor identifies the transaction/s as "suspicious". Even when a transaction is flagged, it will often be determined to be legitimate through the most basic of investigations and there'll be no need to report it as "suspicious" to FinSEC/AUSTRAC or whomever.
