Android ADB devices displays no permission

Run the ADB devices command in Ubuntu (9.10). The returned result is:
List of devices attached
???????????? No Permissions
This means that USB-connected devices can be identified. After Google, I learned that the ADB server needs to be started with the root permission, so I had the following command:
Brian @ Brian-LAPTOP :~ /Developer/Java/Android/android-sdk-linux_86/tools $./ADB kill-Server
Brian @ Brian-LAPTOP :~ /Developer/Java/Android/android-sdk-linux_86/tools $Sudo./ADB start-Server
* Daemon not running. Starting it now *
* Daemon started successfully *

The first command is used to kill the currently running server. The second command starts the new server with the root permission. We can view the devices again:
Brian @ Brian-LAPTOP :~ /Developer/Java/Android/android-sdk-linux_86/tools $./ADB Devices
List of devices attached
Ht848kv04386 Device

The device was correctly identified this time. Naturally, tools like ddms can also be used.

If your machine cannot be identified or is not in the Ubuntu environment, see Official Documents: http://developer.android.com/guide/developing/device.html.

Tip: http://www.blogjava.net/brian/articles/316019.html