The middle of this article has a nice, light historical survey of what the US gov't has done to the dollar in the last hundred years (including a description of the details around EO 6102 -- not as good as @Signal312's #275618).
I generally agree with the conclusion: that the gov't is probably not going to seize butcoin en masse, but I wish the author had included a little about how the "seizure" is really playing out: through increasingly tight financial controls and pushing people toward custodians.