From the post:

"So there is potentially an entity called Tornado Cash that is controlled by certain individuals, and the web address and some of the Ethereum addresses in the notice can be thought of as either pseudonyms for that entity or, alternatively, as its property. At this point, we’re not offering an opinion on whether it was appropriate to sanction that entity—we do not know all the facts that have led to this action—but we would agree that there may be an entity behind those donation addresses and that said entity may be legally eligible for listing. "