Cloned MAC address?

[Bill Stanley]

I was exploring the GNOME desktop and found something interesting.  When 
right clicking the Network management Applet icon there is an item that 
says "Edit Connections".  I clicked on this and then on one of the 
items, "Auto Eth0", which the applet says is never used.  There is 
nothing interesting yet but one of the options is "cloned MAC address". 
  Is a different MAC address reported to the Internet instead of the 
actual MAC address?  I don't intend to do anything or do any editing of 
the settings, I am just curious.

Bill Stanley