1) people who cheat their way into obtaining large sums of money, and don't pay taxes on thus illegally obtained money
2) (a simple trolling word)
3) can also be used to describe people who unscrupulously nick (i.e. stealing money, in British English) and then dig it.
4) can also be described people who legally dig big nicks , i.e make big sums of money
Me: Looks like Big Nick Digger if you ask me.
Your sister: Hells yeah! I'm about to find out fo-sho! If I'm walking funny tomorrow, you'll know why!