> 4) Child porn. This is a big issue for systems like this, but I believe it could be addressed through machine learning algorithms. Rather than a spam filter,

> 4) Child porn. This is a big issue for systems like this, but I believe it could be addressed through machine learning algorithms. Rather than a spam filter, you have a child porn filter, or a whatever-it's-illegal-to-host-in-my-jurisdiction filter. At least in the child pornography case I believe it could be fairly effectively detected, though of course keeping the model up-to-date would be difficult.