OK, my thoughts.
SOPA will not make this gif:
a site-shuttering offense because the main purpose of the site isn't to distribute animated gifs from movies. It's a film commentary site that has practically no relevant infringement going on, aside from a couple of gifs. I guess you could make an argument that because the gifs are actually built into the board that there's some infringement going on, but the bill requires that the site's main reason for existing be to illegally distribute, enable the distribution of, etc, copyrighted material. A couple gag gifs are safe.
Anyway, the point is, it's not THAT that's the problem. It's the lack of due process. If you guys were, say, distributing the commentary tracks ripped from the movies themselves, then they could shut you down because that would be a primary use of the site. "But you can already do that with current legislation, so what's different?" you ask. Well, the difference is that with SOPA they don't have to send you a cease & desist letter telling you to shape up or they'll sue you. With this they can file some documents and get a court order to have your site's domain revoked, get you delisted from google, etc. Now you have to prove you're not violating copyright before you can get your site put back online, and even if you could prove it, it would damage you immensely in terms of lost revenue, lost traffic, lower ranking on google and who knows how well screwing with DNS / nameservers will go. You are now guilty until proven innocent based entirely on one-sided evidence provided by whoever's making the complaint.
Or if you have a blog on some site where people can make their own blog like tumblr or blogger and one of those blogs is targeted. The bill could get all of blogger, including your blog, shut down rather than that specific blog because it's all hosted under one domain.
The bill does define the sort of site that can be shut down with the bill. It's not that vague. There are vagueness problems in terms of what constitutes a website vs a user's created page or section of that website. Something like Flickr could be in trouble if there are tons of users with their own separate pages or blogs all being listed under one larger domain. That's not really defined in the bill and it's an issue because one persons entire blog or page on a site may be devoted entirely to distributing copyrighted content and thus may fall under the bill's definition of what exactly an 'infringing website' is. But this site and forum are safe, as are most sites and forums, because the objective of this site isn't to illegally distribute copyrighted content.
That said, SOPA does suck, it just sucks mainly due to the lack of any sort of due process and the fact that the bill seems to have been written under the idea that websites were still operated the same way they were back in the late 90's. There's not much in there in terms of user-uploaded content, and the lack of definition is what people are worried about.
But if you're flickr or youtube and you have systems set up where copyrighted content can be reported and you clearly state that you don't allow that sort of thing, and you don't market yourself as such, then I don't think the bill could be used to have your site shut down. It's the "I don't think..." part that's in need of fixing.
The lack of due process and the way it may screw up the technical functioning of the internet as a whole is the real issue I have with the bill.