1.5 - Subpoena ISP to get records for which customer that dynamic IP was assigned to at the time. It's all possible - assuming there's something to charge the

1.5 - Subpoena ISP to get records for which customer that dynamic IP was assigned to at the time. It's all possible - assuming there's something to charge the uploader with. But it's likely to be a slow process; for starters, the site will drag its feet about supplying the records. And if the uploader used a smartphone on the Wifi in Starbucks, it gets that much harder to track him. To make a serious dent in this, I think you need some way to dissuade people from running the site.