I only stated why they removed Firewire (did not cost Apple anything)
from the Ipod. It was a big thread to security.
from 2007:
A security consultant based in New Zealand has
released a tool that can unlock Windows computers in seconds without
the need for a password.
Boileau, a consultant with Immunity Inc., said he did not release the tool
publicly in 2006 because "Microsoft was a little cagey about
exactly whether Firewire memory access was a real security issue or not
and we didn't want to cause any real trouble".
But now that a couple of years have passed and the issue has not
resolved, Boileau decided to release the tool on his website.
To use the tool, hackers must connect a Linux-based computer to a
Firewire port on the target machine. The machine is then tricked into
allowing the attacking computer to have read and write access to its
memory.
With full access to the memory, the tool can then modify Windows'
password protection code, which is stored there, and render it
ineffective.
Whole problem started when hackers created strip-down version of
Linux for Ipod and used it in few instances to hack companies
computers thru Firewire's DMA.
In addition to Firewire being expansion bus it is also peer-to-peer bus
allowing networking between computers while USB as peripheral bus
works only in Host-Client mode.