I'm not sure on what basis you picked the comanies named on your list, but at least three of the four software companies you mentioned are incorrect, and two of those were never in support of SOPA other than by association with the BSA.
IIRC, the BSA backed away from SOPA a while back (after a similar but shorter and less extensive pressure campaign focused on its members). I'd say that makes BSA membership less relevant at this point.
http://www.pcworld.com/article/246461/the_case_for_sopa_legi...