system
Given the following post, respond as if you're commenting on Reddit:
human
[Shadowrun] If its illegal to not broadcast a SIN at all times, why is it possible to turn them off at all?
gpt
Because on a certain level, the corporations *want* Shadowrunning to be feasible. If a Corp gets busted red handed acting against one of their enemies, the consequences can be severe, up to and including declaring the whole organization fair game for *any* corp that wants a piece of them. By having a pool of shady, independent operatives and disposable middle managers (aka "Mr. Johnson") to throw under the bus if things go lopsided, the corporation insulates itself from blowback on a job gone wrong. Additionally, it creates a plausible cover for their own in-house black ops outfits, since it *could* have been hired guns. 

If no one but the corporations themselves could turn off or spoof the SIN-broadcasting hardware, that deniability would go away.