SOPA would shut down this site or radically change it's existence (and not neccessarily by Valve)
If it passed, before they shut down the site (if you wanted to be compliant with it) you would have to go through every single post that you have here - making sure that links don't go to copyrighted materials, etc - they could also perhaps take it so far that the links that they do go to don't go to other sites that are 'no good' in their opinion.
In this case, I'm talikg about simplicity here - it would be easier to wipe out your entire database and start over - you would loose everything.
Then for the set up of the new site it would be a posting forum only - no links / pictures allowed. Use of Avatars would have to be proven that they are non-copyrighted materials and therefore would be frowned upon to the extent that no avatar should be allowed.
You would then have to set up a judging panel - one that should include a lawyer to make sure you're compliant - so that when one makes a post it would not be seen by anyone until the item is approved by this panel.
You would have to go through each and every map/model on the site to make sure that those items are also compliant - meaning:
Maps/Models - zero custom textures allowed - the would have to be official Valve content. There would have to be documented evidence of how the item was made, the process by which it was made and the components which make up the final product (i.e. a list of every single Valve texture used in creating it)
Maps - no custom sound tracks period, no use of the pictures in the menus when map starts since it could be argued that the use of Photoshop Etc would be using a 3rd Party Software package to modify the existing software or items derived from that software company and that by doing this it would be infringing / stealing the intellectual property of that other company even though those images are meant top be used in the originals software. It could also open up another arguement by Photoshop for example that they are against the use of their software by people, companies, organization for use that they might have moral issues with. Maybe their board ov governors are against their products being used in producing/promoting violent video games of any fashion.
Tutorials - have they or the use of pictures from Hammer used in the tutorials been approved by Valve? Again another grey area. Does writing up tutorials on another person's software on how to use it constitute trademark infringement since it could be argured that although Valve gives you the license (within reason) to use the product, does that license constitute the authorizsation to write up documentation about that program?
The Smily Faces in the right hand panel - where did you get them? Can you leagally use them? Can you prove that the person who gave them to you actually made them or are you breaking the law by using them.
Ok, well you get the drift - I could go on and on but this is the stuff that pops into mind of the top of my head about the topic.
Who knows, maybe the stuff that I've written will help you out when you revamp the site. Maybe items should be verified by the creators when they submit maps, models, tutorials as to where and how, etc.
Maybe when people sign up they will have to read and agree to a new set of "terms of use" policy that would have to be written up by a lawyer to cover your ass if someone comes knocking on your door. I don't know.
This does bring to mind a verse from Revelation that is as follows:
Men worshiped the dragon because he had given authority to the beast, and they also worshiped the beast and asked, "Who is like the beast? Who can make war against him?"
With the way this act is written and can be enforced - there will be no more "personal freedoms" period. SOPS's/PIPA been designed so that the little guys WON'T be able to fight it PERIOD!