Below is visualization of the email discussion threads around the topic of the infamous (in some circles) httpRange-14 decision that appeared on the following w3c discussion lists: public-awwsw, public-lod, public-rdf-wg, public-swbp-wg, public-vocabs, semantic-web, www-tag, public-swd-wg, public-sparql-dev. Each node is an email (hover over it to see the subject and author), and each edge indicates a reply to another email. Nodes colored red are the emails that originated a particular thread. If you want to see the data behind the graph checkout the RDF or the JSON that drives the D3 visualization.
There is a similar visualization of the people who have corresponded with each other, as well as a detailed view of a particularly long thread that is evident in the graph below.