Dear author of this novel: No, IP addresses are not a data trail. At all. Cookie jars do not perform any analysis of whether or not someone who has valid passwords is supposed to be on a site. Someone’s email address can’t be determined by looking up their IP address. I’ll give you credit for making it five books into this series without trying to talk about how the internet works, but this is the kind of stuff that gets you three stars instead of four or five for your book. If you can’t manage to find someone to help you do the research you need in order to make these hacker scenarios appear at least partially plausible, stay in your lane and don’t use it as a plot device. My kingdom for a novel not written by a geek that at least makes an attempt to get some of this right instead of just spewing stuff because you think it helps your hero.