I'm an Automatic teller machine, ATM for short.

I'M used every single day by at least 20 people

 ATMs like me are found everywhere in cities and states.

 We are in banks, train stations, schools, hotels , stores, and almost any public place.

 Everyday I get used by people who put their cards in and take money out. 

 At the end of every week a man with a gun and big truck comes to put more money into me.

 Sometimes a guy comes in a ski mask and wears all black to  make multiple transactions in the same hour. 

He is suspicious because he uses different cards all the time but I can't do anything about it.

 Many people rely on me when there isn't a bank nearby. I'M probably the easiest public use machine out there. 

All atms were inspired by vending machines

So people could access their money just like they get their snacks