You are running more than a WATT of power to the terminator.
Disconnecting that might cause inductance to generate voltages that
are much too high for computer components.
As the disclaimer in the kernel says: You're not supposed to hot-swap
devices. You are maybe allowed to turn off devices that are not used
for longer periods. I have an external ROM burner and a scanner, and
those only get turned on whenever I use them.
There are also systems that have special hot-swap slots (RAID systems
come to mind).... These can be safely hot-swapped as the designers
assume responsibiltiy that they took care of all issues related to
the hot swapping....
In practise you can hot-swap SCSI devices with just a small chance of
blowing up stuff. At the company a friend works for, they fried an
SGI's scsi bus, external CDROM drive, and the internal DAT drive by
hotswapping the CDROM. I occasionally hot swap my equipment too.
It usually survives.... :-)
Roger.