Given the possibility of a group, could it be a chunk of former Watchers?
I first thought of SilveryK. She is a former Dunkelzahn Watcher, so she probably spent a lot of time gathering intel on dragons and Aztlan. And she is involved in Denver politics as an admin of Nexus and their liaison with Ghostwalker. Also, she inherited a "can-opener program". In
Spy Games, Perri, the other Nexus sysadmin, manage to hack into Jackpoint (and maybe he choose to display a login doing so).
But the theory doesn't hold water, because SilveryK designed and built her equipment from scratch. So she should know even optical computers have a magnetic fields coming from their power source, in
Spy Games, page 166. That post is interesting, because it means someone can get past Jackpoint security and at the same time lack such knowledge on how computers actually work. If it's a group, it can be SilveryK and a bunch of other less-knowledgeable Nexus people using the can-opener program. It can also be a technomancer, as those can be very good at getting through firewall and still not know how a real computer work.