Web Annotation—now a W3C standard—aims to establish a conversation layer on top of the web. By theoretically allowing anyone to annotate any web page content, it’s an ennobling premise and thoroughly web-like: democratic, open and standardised. But with this freedom comes challenges. Content publishers are faced with an anxiety-inducing lack of control over what people say about their content. And nothing in the standard itself protects against conversations devolving into troll-hijacked chaos. The evolution of Web Annotation mirrors that of the Web itself, in miniature, facing off with some of the same big themes of identity, security, authority and freedom.