Well, unfortunately you won't get much of a conversation - you're far more likely to just get a bunch of "No" replies
Mostly the knee-jerk reaction 'no' is from people fearing that this would allow governments, or just powers-that-be, to start blocking anything they disagree with, further regulate its use, etc. Hence my inclusion of the word 'voluntarily' (note that by design it would have to be, since the protocol doesn't mandate and require it in any way - so even if 99.9% of the clients/services adhered, the other 0.1% could still confirm/etc.) The follow-up 'no' comes from people who think that such an approach would effectively split the Bitcoin community (into those who adhere to the blocks, and those who don't), which is not good for the ecosystem. There's some truth to that, though it's difficult to quantify. One of the more worrisome factors there would be if a popular enough mixing service decided not to adhere. Next up is mostly the 'no' responses from people who just dislike any form of oversight and lean heavily on self-reliance and personal responsibility - in this case, "why should everybody else suffer just because of your failure to protect your Bitcoin?"
Can't really blame them, though - this discussion has been had several times before. Not sure how easy to find via search here, but try Google.
