How does SOPA threaten US sites?

In the beginning I was also caught up in the fevered warnings about SOPA passing. But now it seems to me that all the hoopla about SOPA is overblown for domestic sites hosting user-submitted content. Here's why:

A) If you are already in the US, then the justice department and DHS (of which ICE is a subsidiary, I believe) have already been able to authorize the seizing of, and seize domains registered in the US. I repeat, this has ALREADY been going on, as many of you know, and it hasn't caused a huge problem for the internet.

http://www.dailychanges.com/seizedservers.com/

So the horse has left the stable, as it were, for domestic sites, and it can't get worse with SOPA, as far as I know.

B) If you are a Foreign Site, then it can get quite a lot worse, but only if you are a site which would be "subject to prosecution under U.S. criminal law if [you] were located in the U.S." -- this thanks to an amendment introduced by Chairman Lamar Smith himself:

http://judiciary.house.gov/issues/Rouge%20Websites/Summary%20Manager's%20Amendment.pdf

Now, this new language seeks further to define what "Rogue Site" means. It removes the "Global Tech willful blindness standard" as well as the "enables or facilitates" language (!!)

I think people should be aware that this new amendment was accepted by the Judiciary Committee. In addition, the following were changed:

* The court at its discretion might focus its order only on a subdomain or portion of the site.

* ISPs cannot be ordered to block a subdomain

* ISPs are only required to take measures they determine to be the "least burdensome, technically feasible, and reasonable"

* Any action against rogue sites pertains to foreign sites, i.e. those that are located overseas, or that are unreachable domestically and whose owner or operator is located overseas. It excludes sites like facebook, youtube, etc.

And very importantly for those concerned about the security of DNS:

* It allows a provider to NOT carry out an order on a finding that it would "impair the security or integrity of the system".

And therefore, SOPA is now rather benign, it seems to me. Its primary effect would be to disable the pirate bay and other sites like that. Perhaps megaupload.com . It still sucks for foreign sites, but even so, it doesn't touch domestic sites, and ISPs can refuse to do it, citing difficulty or security issues.

Please correct me if I am wrong. I posted this in order to get more information and inform others.