A man in Ireland is arrested on child pornography charges, and a network of ostensibly anonymous and invisible websites goes down at the same time. It’s no coincidence, and this latest chapter in the story of privacy on the Internet shows that it’s hard to hide, even in the “deep Web.”

“Just as there is no such thing as 100 percent security, there will always be an arms race to maintain anonymity,” wrote Alan Woodward, a security and cryptography researcher and professor at Surrey University, in an email to NBC News. read more