Really now.
Let me see here. The error you're getting is....urllib2 HTTP 403. I can see how that's not in the EAQ with those words.
The forum, however is searchable.
http://www.minecraftforge.net/forum/index.php/topic,11001.0.html
BAM, it is in the EAQ:
Also:
And wtf do you think you are? You're not a MODDER and this is the MODDER support forums.
I'm using forge to create mods, therefore I'm a modder, am I incorrect? On the other hand, excuse me but I was searching the topic for 403 errors.