Originally posted by Rolex
Have I been smoking something? What kind of comment is that? It's not (usually) visible on the net, but I'm not interested in having a laptop that has logged into any ISP (which you, of all people, know logs the MAC address), therefore having a traceable history other than my own.
I seriously doubt that most ISP are logging MAC address information. The only ones I know of that even care what your MAC address is are cable companies that don't use PPoE and that's only so they can tie your service to your network card. This is to prevent fraudulent access to thier network. Most cable companies have abandoned this and moved to PPoE or some other form of Authentication because MAC address cloning is a common feature on most Cable/DSL routers.
The MAC address (hardware address of your network card) is only sent to your ISP to assign you an IP address. This is destroyed when your IP lease expires. True, most DCHP servers can keep logs but all they would show is this network card received an ip from their server on a specific date.
As far as the HDD there are many forensic tools available that will completely clean a HDD of any data. If you are that paranoid regarding what may have been saved on it.
Seriously, I think you are stressing about a whole lot of nothing.