When using Intent extras, pass an Id rather than the object as Intent extras 'could' be intercepted and read be a malicious app.

IntentExtraEample.java

	//bad passing the whole paracable object
	public static Intent getStartingIntent(Context context,
			User user) {
		Intent i = new Intent(context, UserDetailsActivity.class);
		i.putExtra(EXTRA_USER, user);
		return i;
	}

 //better to pass just the ID to lookup the user details
	public static Intent getStartingIntent(Context context,
			String userId) {
		Intent i = new Intent(context, UserDetailsActivity.class);
		i.putExtra(EXTRA_USER_ID, userId);
	  return i;
	}