basicaly SOPA or the stop online piracy act, is a blunt tool funded by and lobbyed by, large companies who are involved in the media release markets. (think disney, time warner etc) and related stuff like music.
if it was intended to target the mass piracy systems then they may have a point (i resent having to rpelace CDs every few years because they wear out) but the simple fact it can be used by private companies to silence a critical werbsite.
for example
I find all the music released by Nickleback to be crap.
that comment, as it includeds a referance to a bands name, which is copyright, is enough under the legislation, to have SSish shut down by the owners of the copyright.
i could comment on an article in a music magazine online and say that nirvana is a better band than nickleback and even as its an unstubstantiated post on a user reply that is enough to have the website closed down.
i link to a wiki page and thats enough to close the site down.
i put a utube vid link up of a music vid, even one put up by the BAND themselves, its enough to close a site down.
wiki obviously discusses things which are copyrighted, but does so not for profit, however under the legislation the smple fact of having information about anything is enough for it to be closed.
facebook? put up a picture you take of a band, or of a poster, thats enough for the legislation as it is written
and it is not limited to US sites, this is the thing, it is a blanket thing.
when the chinese have a blanket ban on websites from the government its called censorship. when the US permits private business to blanket ban websites its called piracy prevention.
http://www.youtube.com/watch?v=uvXo4sGB7zM
that vid is quite accurate and amusing.