I've just thought of another way in which all four of these novels are connected. There seems to be a running motif of murder and violent attack, but the kind of attack that's unexpected and unprovoked. Reading about the Digibomber (and the Finn That Got Blown Up) reminded me of the Texas Highway Killer, which made me think of the A.F.R. and other Quebecois terrorists, and, to a lesser extent, the random and violent nature of the V2. Since all of these novels also deal in some way with war, I find all these instances of violence occurring close to home and without warning terribly fascinating in context.