How the world's biggest dark web platform spreads millions of items of child sex abuse material - and why it's hard to stop

Child sexual abuse material is rampant online, despite considerable efforts by big tech companies and governments to curb it. And according to reports, it has only become more prevalent during the COVID-19 pandemic. This material is largely hosted on the anonymous part of the internet — the “darknet” - where perpetrators can share it with little fear of prosecution. There are currently a few platforms offering anonymous internet access, including i2p, FreeNet and Tor. Tor is by far the largest and presents the biggest conundrum. The open-source network and browser grants users anonymity by encrypting their information and letting them escape tracking by internet service providers. Online privacy advocates including Edward Snowden have championed the benefits of such platforms, claiming they protect free speech, freedom of thought and civil rights. But they have a dark side, too.