@gollum,
I can tell you about financing for the cannabis industry (I wrote about it for work fairly recently).
Most conventional banks will not lend money to high-risk industries. Cannabis is one, but so is real estate (realtors may be alone with a homeowner and get attacked, or people fall in houses during showings). There are a bunch of others, many of which are obvious, such as firearms manufacturing and bail bonds.
So companies like this get their funds elsewhere, such as through Angel investors (mom puts up cash), venture capitalists, crowdfunding, and bootstrapping (the owner pays from his/her savings until the company starts making money).
As for bank accounts, they are likely using online banks, many of which have not as strict requirements. They may even be getting loans through them.