I finally received a reply from Michael Danby.
After four letters over several months, I finally received a reply from Michael Danby (my local member of parliament). This was the first actual reply to any of my letters (I won’t count the form letters from Conroy which were basically an insult). While I was not expecting Danby to go against party policy, I was pleased with the generally positive tone regarding internet freedom.
Of course since then both Conroy and Gillard have reafirmed the filter policy.