Android: "wipe data/factory reset" won't delete all directories in '/sdcard' I'm trying to reinstall my Asus Transformer TF101 with Cyanogenmod, I select the "wipe data/factory reset" option in the ClockworkMod Recovery menu, but after installing it I find that the original directories remain in '/sdcard' (I expected them to be removed).

Is it safety if I delete this whole directory just by "rm -rf /sdcard" in the shell?

Thank you very much.
/sdcard is part of the Android file system structure. This is where it mounts your external drives, the SD card. You shouldn't delete this partition. But you can delete the content of the directory either using an app or using rm -fr /sdcard/*