Necesity of policy file?

programming flash
1

Do i always need a policy file to load external images?
In Flash IDE all is fine, but after checking in browser images won’t resize… (ooops I haven’t tried SecurityErrorEvent listener… oh, I did! try…catch has thrown Security Error).

private function _thumbComplete(event:Event):void {
  try {
   event.target.removeEventListener(Event.COMPLETE,_thumbComplete);
   event.target.removeEventListener(IOErrorEvent.IO_ERROR,_thumbIOErrorHandler);
   event.target.content.smoothing=event.target.loader.tabEnabled=true;
   event.target.content.width=event.target.content.height=100;
   ...
}

My question is: Do I need a policy file to access smoothing, width or height of image? This is riddiculus, help tells only about BitmapData.draw().
I tried to comment that smoothing and still same problem.
This would be horrible to put there a policy file… since i need a forgotten password…
Is there a possibility to ommit using that policy file?