Last week, Jonathan Mayer, a graduate student at the Stanford Institute for Internet and Society, released a blog post reporting that Epic Marketplace, a major US advertising network and member of the Network Advertising Initiative (NAI), is history stealing via the CSS history hack. This declaration has instigated an ongoing conversation in the internet security and advertising worlds about the ethics and legality surrounding these tactics, especially once users have opted-out or activated Do Not Track. We find this discussion particularly interesting as we’ve seen these methods used by the blackhat affiliates that we monitor on a daily basis.