"Chris just yelled at me because i used his cell phone, he's so firm."
"Harry is wearing his Save By the Bell fan club t-shirt, he's so firm."
They opperate in very similar ways to other criminal organizations like the Italian/sicilian mafia and Irish mob, like them, firms also have traditional values of respect, looking after your family and the rest of the firm and the code of silence.
Their criminal activities are mainly for financial gain, and they include; drug dealing, gun running, smuggling, extortion, armed robbery, protection rackets, kidnapping, the list goes on. Some larger firms opperate on an international basis, you will find quite a few British firms operating in places like the Costa Del Sol in Spain, and in other parts of Europe too.
Guy 2 - "Will you go down to 20?"
Guy 1 - "No, $30 firm."