Why don't we use ferrites??

Hey all,
When I pulled apart an old scanner and printer I kept finding these
metal tubes that have wires wriped around them before going to their
final place. I also find this on my digital camers wire and other
wires that connect to the computer. I later found they are
called "Ferrites" and are used to decrease noise.

Why don't we use them in our stuff, like the camtronics board or the
wires going from the drivers to the steppers?

just wondering

thanks
tauseef