This is a really good video about SOPA, but some facts are slightly missing.
The US would seek extradition to prosecute breakers of SOPA abroad like they do with existing copyright laws.
The US currently controls domain name registration so would use that as a weapon against governments, people or organisations that didn't comply with their domestic SOPA laws.
And SOPA contains a section whereby anyone discussing or educating people about circumventing SOPA would fall under SOPA's restrictions. In the case of the video I have posted above that would mean VIMEO could be taken down and without due process or representation.