Preventing bcm43xx module from autoloading?

[Derek Frye]

Hi, I was wondering, how is Ubuntu preventing the bcm43xx (or any other) 
module from autoloading (if appropriate hardware is present) if the 
module is not on the blacklists in /etc/modprobe.d?

# $ find /etc/ -type f -print0 | xargs grep -Hin bcm43?x | wc -c
0

Thanks,
--Derek