Comment 6 for bug 504440

I cannot see a regression here: In up-to-date Jaunty (supported updates, at least), the "safely remove" option that I see in desktop and nautilus sidebar is actually called "Unmount" and it does the same as Unmount does in Karmic: it unmounts the filesystem.

Unmounting the filesystem does not prevent raw blockdevice access (e.g., fdisk or dd), as opposed to Eject and Safely Remove, which actually turn off all access to the media. Therefore, these options are safer that unmounting (although calling these before a dd has ended will kill dd and could corrupt the data in any case).

In addition, "safely remove" shutdowns the device so that it has to be reconnected to use it again (as computx notes, it is not a question of modules or services that could be reloaded without physical reboot AFAIK). This avoids electric transients, which could eventually damage the microchips (even those designed for hotplug). Despite the fact that this is not a very common issue, it is a progress that Ubuntu is implementing this, that they do "more" than unmounting.