Was thinking this morning while waiting out a bounty on top of the Maze Bank building at night in-game that it would be cool if you could knock out the power to a portion of the city. Maybe you could hit a transformer and then the power to a portion of the city goes out for a period of time. Or there could be other methods to take the power out (maybe be able to buy an EMP drop from Merryweather?)
No traffic lights (NPC cars that no longer have traffic signals turn streets into a parking lot or crash), no lights (easier to hide) and no cell service (no power to the cell towers.)
The finer details of it would have to be worked out, but effectively could be used as a tactical weapon and turn that portion of the city, briefly, into weapons only (no calling Pegasus for a tank or to put a bounty - couldn't even call Mechanic - if you were in that portion of the city.)
During the day, the stealth aspect of all lights off wouldn't be there, but still you could turn the traffic lights off and take cell service out for a portion of the city.