the reprogramming works by pushing and popping values at certain io ports on the card to manipulate the mac address, it's actually not something that's public information but rather something i've stumbled upon in doing security research. each mac address is supposed to be unique but they can be faked in multiple ways. one way is by reprogramming the card if it's allowed (most don't allow it, but some do allow it and don't publish that is can be done), another way is to install kernel hooks so that when a program asks for the mac address of the card you interecept the message and reply with your own mac address... that way actually works with all cards and is the current way i would do it. and there is no database of usable addresses, each manufacturer has there own ID code which they use and it's the first six characters... for example: 08:00:69 = Silicon Graphics, 00:02:B3, 00:03:47, 00:04:23, 00:07:E9, 00:20:7B, 00:90:27, 00:A0:C9, 00:AA:00, 00:AA:01, 00:AA:02, 00D0B7 = Intel... so you've got this six character identifier and then as they start production they just roll the last 6 characters for each new card. but mac addresses don't really mean shit, they're only recorded at the routers (via netflow) for identifying an IP address against a mac address... one of the ways the FBI will convict hands down is if they enter router logs into the record and enter the mac address that was used on the computer that was siezed into record and the case is pretty much closed and yer fucked. you gotta be bleeding edge technical if you want to escape the law, atleast in cyberspace... lol, this must sound super nerdy.