There are over two billion people on there. How about paying their users for finding and reporting content? A reputation system to find and pay trustworthy people to clean up. Thereby delegating the task back to the scale where it belongs, some money and incentives too.
I've been thinking about a online bounty hunter service to do exactly this.
Next step - how to prevent Sybil accounts created by the bounty hunters from generating new mal-content on an industrial scale for bounty hunters to identify for reward.
