Ordinarily it doesn't refer to much other than a series of acts that a particular country is willing to break it's own norms in order to prevent from continuing.

Originally, it just referred to asymmetrical warfare where there was no chance that the weaker side could win through battles, so instead they commit random, surprising violence to the stronger in order the keep them individually paranoid and terrified, and eventually to break their will.

I think the term was originally coined by Anarchists as an ideal, humane, effective war strategy. Propaganda of the deed.

Terrorism is generally the use of tactics that inflict terror on a civilian population to get a desired effect. The specific exclusion of official government and military actions is motivated reasoning on the part of government officials, who prefer to use nicer euphemisms to describe their own actions.

> on 28 March 1945 the Prime Minister, Winston Churchill, sent a memo by telegram to General Ismay for the British Chiefs of Staff and the Chief of the Air Staff in which he started with the sentence "It seems to me that the moment has come when the question of bombing of German cities simply for the sake of increasing the terror, though under other pretexts, should be reviewed...."[13][14] Under pressure from the Chiefs of Staff and in response to the views expressed by Chief of the Air Staff Sir Charles Portal, and the head of Bomber Command, Arthur "Bomber" Harris, among others, Churchill withdrew his memo and issued a new one.[14] This was completed on 1 April 1945 and started instead with the usual euphemism used when referring to strategic bombing: "It seems to me that the moment has come when the question of the so called 'area-bombing' of German cities should be reviewed from the point of view of our own interests....".[15]

(Incidentally, I think you have to stretch even my definition of terrorism to include hacking.. having your power turn off or your bank shut down by hackers is certainly destructive and disruptive, but terror inducing? That's a stretch. It's not like you're trembling in fear wondering if a bomb is going to crash through your roof tonight.)

The definition you offer doesn't appear to be compatible with either half of the sentence I asked about:

>>> it sets a precedent that licenses american civilians to be terrorists against other nations, which has historically been a privilege reserved for the intelligence community.

in that, as you note, the activities being endorsed here would not qualify as terrifying, but also in that this is generally not something the intelligence community tries to do.

> The definition you offer doesn't appear to be compatible with either half of the sentence I asked about:

Yes, I agree that privateer hackers aren't terrorists and I wasn't trying to bolster that claim. But it's not because they're given letters of marque, government sanctioned terrorism is still terrorism as far as I'm concerned. Rather, privateer hackers aren't terrorists because they generally don't use tactics specifically intended to inflict terror. Rather their aim is to disrupt industry and the economy.

If hackers were (hypothetically, surely) to cause a liquid natural gas plant explosion, is that less terroristic than causing a truck, a data centre, a wastebin, a church, or a policeman's pub to explode? All are examples of major terrorist attacks in living memory, and it's strange how intuitively it seems less like terrorism to hit an LNG plant, even though several workers would likely not survive and it's going to cause knock-on social instability from price jumps.

When you attack an economy, you are making people fear starvation instead of murder, but it's still a violent act that instills an irrational fear that you are responsible for as a means to affect policy. I wouldn't accuse you in particular of being able to rationalize it as something like, "it's not murder if you starve them," but when you destroy critical infrastructure that supplies their food system as a way to put fear into their economy, that's precisely the rationalization of that attacker. It would be interesting what the argument for it not-being terrorism would be though.

> If hackers were (hypothetically, surely) to cause a liquid natural gas plant explosion, is that less terroristic than causing a truck, [...], a wastebin, a church, or a policeman's pub to explode?

If there is a war going on, then yes definitely. A LNG plant is a strategic target, same as the data center. The truck could also be argued as well. But a waste bin? What strategic aim is there in blowing up a wastebin, other than instilling fear in the local population? If the sole strategic impact of an attack is the terror it causes, that is terrorism. Of course you can get into shades of gray, like the truck. Maybe the truck was being used to transport materials for the war, or maybe not.

Ever since before WW2 the legitimacy of a target in war time didn't matter anymore. Personally I go further, if one party can use, e.g., cruise missiles to blow up stuff the other party should have the same right blowing up stuff. Even they use other means for lack of cruise missiles. As soon as you explicitly target civilians and non-combatants it is terrorism or a war crime, regardless of the means. We owe it to WW2 that strategic bombing and unrestricted submarine warfare are considered legitimate strategies, simply because both sides used it and the victors wanted to avoid casting and cloud over their tactics and people like Harris.

The wikipedia page for strategic bombing is where I pulled that Churchill quote from. When strategic bombing specifically targets a civilian population with the intent to cause terror, by Churchill's own account, that is terrorism (the term 'terror bombing' has been used by historians and commentators to describe the practice, and I think it fits.) Both sides of WW2 used terrorism extensively. They normalized it, but normalized terrorism is still terrorism.

"bombing of German cities simply for the sake of increasing the terror, though under other pretexts"

If hackers disabled your grandma's home heating as well as her phone line on a day where the temperature was below zero, locked up your car's brakes on the freeway because they discovered the entertainment system was connected to the vehicle bus for some idiotic reason, or found a way to do naughty things to gas pipelines, you might be terrified.

I assume that all of that is currently possible and I’m not terrified.