swbell DSL bug ?

[batrox () SWBELL NET (Ryan Sweat)]

     Southwester Bell is a big provider of dsl access in some parts of the US.  Dhcp provides an IP address and the 
lease expires in about 72 hours.  They claim the IP cannot be changed, however when playing around last night, I found 
if you install another ethernet card, and switch the cable to the new card, it happily gives you another IP address.  
The dhcp server must rely on mac address when providing a lease for an ip.  This could pose many problems.  How can 
accounting be kept when a user can change his ip whenever he likes?  I have more testing to do, but I do not see why 
you couldnt install a few nic cards and get ip address for each one, which swbell would like to charge you much more 
money for.  I am looking into a way to change the mac address in windows. I know it can be done in linux through 
ifconfig.  Maybe somone has experience in this ??

batrox () swbell net