Members sub forum are only available at the platinum membership level http://ball-pythons.net/forums/annou....php?f=89&a=19 all it takes is for one member to have that membership to open their very own forum.
I am pretty sure if a group of people wanted their own private group bad enough the could elect one person to be in charge of that group and come together to get some funds.
Other members participating in that sub-forum do not need to have any type of membership.