Treason is a crime. Crimes are dealt with by arrest, trial, conviction and sentencing.
Responding to purported treason by assassination is a cowardly, banana republic approach.
All those poor Confederate soldiers in Picket's Charge. They should have been arrested, not assassinated by Federal marksmen with unfairly-accurate rifles.
It is a statistical certainty (p 10e-1111111) that anti-Nazi German soldiers and civilians were killed by US forces during WW2.
I don't like the government having too much power, but I'm not sure I understand why the ACLU is getting involved in this if it is not being done domestically against American citizens. What's done in war time on foreign soil against non-American citizens doesn't seem to fall within the domain of the American Civil Liberties Union.
It is easy to understand, once you realize that they are on the other side.
A rock store eventually closed down; they were taking too much for granite.