Banks are required to file Suspicious Activity Reports (SARs) for anything unusual or, erm, suspicious, regardless of the dollar amount.

Exactly this. Algorithms have moved well beyond a simple "> 10000", and banks are interested in enforcing this, since the penalties are very signficiant (vastly outweighing any profit to be made looking the other way), and the modern anti-terrorism/anti-money laundering treaties are fairly non-gamable (in that they set outcomes and high-level behavious which are expected, rather than giving a precise set of criteria and rules that can be gamed).

Unless regulations relax, there will be an ongoing profitable business for people who sell software that does behavioural analysis on compliance-related cash behaviours for the finance sector.

So, exactly what part of that qualifies as, "more to add than what the wikipedia article spells out?"