Without a contrary definition of "in concert," I could see that as covering any site with an affiliate program. For example, Amazon provides automated revenue sharing for inbound affiliate links. Let's say some third-party affiliate site markets Amazon as an ideal venue for "engag[ing] in, enabl[ing], or facilitat[ing], violation of [...some existing laws...]". Under the wording of what you just posted, Amazon would now be subject to DNS blacklisting and termination of payment processing.
"They'd never shut down Amazon," you say? Well, so what? They would shut down some smaller Amazon-like site. History has shown that the RIAA and MPAA (and/or their members) will do whatever they can get away with, and sometimes more (see Megaupload+Universal). AIUI, SOPA gives legal force to mere accusations coming from a major copyright holder.