> Armed robberies are done with profit motives by professionalized members of the organized crime. By definition these people have access to the kind of organization and weapons you need to mount such attacks.

Really? Maybe read up some more, OC scale mafia groups weren't doing many of the bank raids of the US 1970s / 1980s - in any case these are still well below my bar on what constitutes a "very strong force".

> Also, I think you massively underestimate the sheer size of an IA data center.

You think wrong.

> If you want to destroy one with grenades you're going to need a literal truck load of grenades.

Exactly right, or rather several drums of farm grade fertiliser, diesel, ball bearings, a stolen truck, and somebody (or two) prepared to do a ram raid. Groomed idealogues or addicts with debt have all been used for such things.

Or, as already mentioned, drive parallel and mortar the centre from one end to the other, achievable by small discontent militia types (who abound in the US).

Serious question time: Are you honestly unaware of Timothy McVeigh? Would you describe him as "a very strong force"?

* https://en.wikipedia.org/wiki/Timothy_McVeigh