But "equivalent economic activity" seems a bit weak. A butler or security guard can be paid to open the door to visitors. So that's "economic activity", right? It doesn't mean they're not required to respond to a search warrant. And legal discovery can be very expensive.

Writing a simple software patch and recompiling doesn't seem all that hard. Rewriting the entire OS is a major undertaking. It may require passing new laws, but it seems unlikely that we'll end up with a bright-line rule where touching any line of code is forbidden. More likely it'll be a gray area where the line is drawn somewhere in the middle.