Similar to clam baking, but instead of hot boxing your car or other small space (such as a shed, porta-potty, etc.), you and your friends haze up a small banking booth. Very illegal and extremely hard to pull off because you have to insert your own bank ID card to gain access to the booth, and because there is almost always a security camera in the booth. This only makes things more exciting, and is definitely something worth bragging about if you can pull it off somehow.
NOTE: It is not necessary to withdraw funds from your account while clam banking, but it can add some fun to your experience as you struggle to remember your password while smoke floats in front of your face.
The other day I was riding around with Johnny and two bitches and we were looking for a place to smoke. We saw a Bank of America booth in a parking lot and went clam banking. The booth was so smoked up we couldn't even see the security camera!