Not at liberty to disclose the "money" part of how and what. But it is very interesting. Most of what you see available on the net are regular practices.
The other stuff...you will know when you do something and we find out. It's not always the US which catches this stuff. Remember other government and agencies are not subject to US laws and can sift through the data for us and then give the data to us under many information sharing agreements. Pretty simple and straightforward.
Basically, if you want to catch someone with money in the US, have the UK or South Korea do it...and give the info to us...best way around US laws. You can also go through the FISA and other agencies (Dept. of Treasury) or other organizations.
It's a multi-layered process we use to get stuff. All of this info is available on the internet...except for the more sensitive practices.