Nobody seems to have picked up on the "external" spam filter part of the response. My guess is that Y! uses some somewhat dodgy external providers of spam/cont

Nobody seems to have picked up on the "external" spam filter part of the response. My guess is that Y! uses some somewhat dodgy external providers of spam/content filtering. Historically, external providers that block inappropriate sites have considered such lists to be their proprietary information, but when those lists have been revealed, they tend to have a pretty heavy political agenda. Peacefire has some reports that detail this: http://www.peacefire.org/ http://www.peacefire.org/ (So, I think the reason for the Y! block was likely an unaccountable third-party, but I think the Twitter block is pretty odd.)