Yeah, but false positives would cause non-hilarious problems.

As long as there are so few sites that do this you could actually just check the list by hand before banning them from the index.

Doesn't Google provide a DNS server, too? If it was for me, they could delete if from the DNS server, too. In general I would like to have a DNS server that simply eliminates such sites.

At the same time, they could also knock down all houses that I am forbidden to photograph and burn all items that I am forbidden to photograph.