Becuase Craigslist supposedly filters these ads. I'm not saying Craigslist should filter these ads. I'm saying they already do filter these ads. So if there are

Becuase Craigslist supposedly filters these ads. I'm not saying Craigslist should filter these ads. I'm saying they already do filter these ads. So if there are still problems the question becomes, why does your filtering not work? Your ISP is doing no such thing (well, unless it's Comcast)