Indeed. If I were among these 84,000 site owners, I would be talking to a lawyer about a very large libel suit.
The United States Department of Homeland Security (DHS) should at least now make clear that all those sites were unrelated to that kind of activity. A very simple way of doing this that costs next to nothing is by publishing a list of those 84,000 domains at their own site saying they had nothing to do with it. That way, site owners could link to that page and clear their reputation.