A Web server hosting www.example.com and example.com aren't necessarily the same. When typing a URL into the box, he prefix "www" is getting chopped off by the backend irrespective of this fact.
True, but for the purposes of the game, it doesn't really make a difference, as www.example.com is unlikely to have a different favicon than example.com. So I am clipping them just to make it simpler to input URLs.