We’re going to have GNDT updates where nobody except the anonymous Hacker and the owner of the target Codename knows whether an update was legal. If it’s possible to make good and bad choices of update, anonymous players will be tempted to make bad (and illegal) updates to rivals: either the true controller objects and blows their cover by doing so, or they suffer in silence. In either case the anonymous hacker loses nothing.

Maybe we could go a bit Top Secret Spies here: decide that subroutines are generally a positive thing, and allow Hackers to distribute them to anyone. You’ll probably want to give them to your own Codename, but won’t want to be too obvious about it.