Conspicuously absent: Berners-Lee and Bray.
Unfortunately, not so. e.g. http://www.telegraph.co.uk/technology/internet/8030467/Inter...
The Digital Economy Act he is complaining about in that article - which, like SOPA, included provisions for national censorship in the name of copyright - passed by a large majority. Most MPs were not present for the debate, but simply voted according to their party line.
That's the case in UK politics. The 'party whip' is used, and only in uncommon cases is a 'free vote' allowed.
EDIT: Just realized he is British (thanks to the other reply). Do you believe his silence (if any, again I can't find much on his stance) relates to his citizenship?