While I am a little late to the party, I'm still here to show my support. As well as the more well known concerns about SOPA, I also feel that it would prevent progress online, as small websites starting up would not be able to defend themselves as well as the large websites who can afford good lawyers and, more importantly, SOPA screams of potential corruption. Thinking of all of the ways it could so easily be abused terrifies me.
People probably can't read this though.