Unable to fetch profile pic using graph api Facebook sdk 4.0

I am unable to fetch image using

 Bitmap bitmap = getBitmapFromURL("http://ift.tt/1Dm7y3w");
            if(bitmap!=null)
            imageView.setImageBitmap(bitmap);
            else
                Toast.makeText(getActivity(),"null it is",Toast.LENGTH_SHORT).show();

Where getBitmapFromURL is

public static Bitmap getBitmapFromURL(String src) {
        try {
            URL url = new URL(src);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream input = connection.getInputStream();
            Bitmap myBitmap = BitmapFactory.decodeStream(input);
            return myBitmap;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

But when I use below everything works fine

        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);

But I have read there Strict mode in android 2.2 that this policy is not safe to use and not just this, it is also blocking my main UI for few seconds.

I want to know first, why I am unable to fetch facebook profile pic without using above policy and Is there any way that I can avoid above policy and may able to fetch my profile pic? Thanks in advance :)