If the group expects to be dealing with a spider, this sort of thing is probably on the hacker's mind already. Any drone network that's part of a site's security may have this sort of wandering IC anyway, that's pretty standard for mid- to high-level Matrix security.
Keep in mind how often drone whisperers turn up as enemies (which, from what I've seen, is seldom). I'm going to increase this a little for my own game, 'cause the group's rigger actually has himself kitted out to be able to hijack drones, and he needs the chance to do so once in a while.