A quartet of senior citizens in Georgia (the state) were recently arrested for plotting massive terror attacks. They were pseudo-militia types, concerned about the expansion of the US government into a tyranny and inspired by Tim McVeigh. They had a bucket-list of officials they hoped to target.
In some regards they followed the typical profile for far-right terror in the US -that is expansive and violent goals - with limited capability. By comparison leftist terrorists in the US (say ALF/ELF) tend to be well educated, disciplined, and focused in their targeting and operations. As one analyst who has studied domestic terrorists, the rightwingers are dumb but unstable and violent.
The prospects for their plots' success, including making a WMD from ricin (which has proven pretty much undoable even for nation states), were very low. The FBI spent months infiltrating their meetings at the Waffle House and their homes. One is forced it wonder exactly how the FBI came to be aware of this cell of geezers.
Overall, terrorism appears to be a young man's game. The leaders may be older, but the actual operatives tend to be young. There is no obvious reason for this (unless the plan is specifically for fedayeen attacks). Elderly operatives should be less suspicious when reconnoitering targets or planting explosives. But there are few cases of this occurring.
The image of an angry young men spouting nihilistic radicalism is common, and even a bit sympathetic. The same anger coming from someone forty years older seems only pathetic.