The NSA should be performing signal and human intelligence operations around the world to ensure the US can track global events. While the Internet is a key tool for this, it doesn't make them the "internet cops" of the US.
The FBI should be doing this, not the NSA, considering the FBI is actually the "US Police".
The government has made representations that we're facing a "cyber warfare" threat, and NSA is a paramilitary organization with a big role to play in conducting such a conflict.
The FBI is an investigative agency. They aren't beat cops. They aren't soldiers. They do have a counter-intelligence role.
From a threat POV, consider how dependent on gasoline and diesel the US economy is, and what the impact of disruption would be. If an attacker could disrupt fuel supplies in key areas or highway corridors, they would cause all sorts of chaos and economic damage.
As Americans, we've been very lucky to have two oceans protect us from the shift in warfare from the battlefield to total war, with the exception of the US Civil War. Our global connectivity changed the threat landscape. That's not a police matter.
"NSA/CSS has two interconnected missions: Signals Intelligence (known as SIGINT) and Information Assurance. Through SIGINT, we gather information that America's adversaries wish to keep secret. Through Information Assurance, we protect America's vital national security information and systems from theft or damage by others."
In the NSAs charter, the term "National security information" refers to classified information and "sensitive but unclassified" information, and the scope includes those systems. The scope does not include protecting all systems that might have national security implications, the NSA has no regulatory authority or requirement to do this.
If your corporate operations are vital to national security, congratulations! You've made it big! Also, you should take security seriously.
This should be an agreement between you and the rest of society (read: laws or standards). Government agencies responsible for the security of the nation should probably be looking into these types of things, and if they come across your RS232->Ethernet-dongle-that-explodes-Tampa they should a) notify you, b) offer assistance if required (for a price) and c) fine and/or arrest you if you are a serial offender.
Serial offender? I can't believe I just typed that...
It was established in 1952 by a presidential directive from Harry S. Truman in which he specified its mission as
to provide an effective, unified organization and control of the communications intelligence activities of the United States conducted against foreign governments, to provide for integrated operational policies and procedures pertaining thereto.
It's probably the equipment makers obligation to have this kind of internet-wide scan done on their devices. A central agency may not even know what's out there, and it's not really reasonable or efficient to have it be the gas station owners problem. Well it is kind of their problem, but it's really stupid to expect every station owner to solve an internet security problem themselves.
The NSA should be performing signal and human intelligence operations around the world to ensure the US can track global events. While the Internet is a key tool for this, it doesn't make them the "internet cops" of the US.
The FBI should be doing this, not the NSA, considering the FBI is actually the "US Police".