logging into youtube from android

Question

I am trying to log into you tube using the following code

mService = new YouTubeService("Nothing", developer_key);

//Authentication
try
{
   mService.setUserCredentials(mUsername, mPassword);
}
catch (AuthenticationException e)
{
   Log.v(TAG, e.toString());
}

but I am getting:
ConnectYouTube: com.google.gdata.util.AuthenticationException: Error connecting with login URI

This code seems pretty basic to me and I can't figure out what mistake am I making here.