It it uses nano tech it would the pink goo kind which can't be reprogrammed. So unless it's in the nanites from the get go you should be safe.
Muhuhahahahahahaahahahahahahahahahahahahahaha!
Actually, I am not sure if I progressively find some evident details about the Sybil, or if in the end I feed the Freelancers (or at least, the possibility they have to make us stress about it;)).
For the nanite part, we don't know if they act directly, through their programming, in which case you are right Damien, or as a relay for something else. Remember, a little things are not working in conventional ways here.
Sometimes it feels like the nanites could be the medichlorians the Sybil needs to express its force. Again, that's gonna be nasty.
Can't wait to read the fluff about that.
About Grimy and other things, I don't think that the devices brought by the victims will help so much. Partly, indeed, and I like the irony, but the discussions in the other thread about wireless seem to imply a very wide number of connections through the nearby Matrix. But yeah, it could happen that your own devices (at least, not all those wifi enabled but those with processing power, huge difference) will help nail you.