I am in favour of a class action suit against the US government for this action. Even if the exchange was liable for criminal activity the depositors are not liable. Wells Fargo in 2008, (Wachovia) laundered $378.4 billion. In May 2015, five of the largest banks in the world—JPMorgan Chase, Citicorp, Barclays, The Royal Bank of Scotland, and UBS—were fined $5.7 billion in a settlement over charges of market manipulation.
In July 2012, the United States Senate submitted a report accusing HSBC Holdings laundered funds from Mexican drug cartels. The total amount is impossible to gauge but a single affiliate exceeded $7 billion in one year.
In lawsuits filed by New York state and federal authorities in 2011, Bank of New York Mellon was accused of scraping $2 billion from pension funds throughout the US by inflating foreign exchange fees and defrauding customers out of that money. They pocketed the difference, which totaled more than $2 billion. In 2015, Bank of New York Mellon agreed to pay a $180 million settlement.
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I could go on but the point is that while an institution may be fined - the depositors with no criminal activity are not liable but the firms can be.

I know of people who live in other countries where the money stolen from their accounts by this action of the US government represents several years of personal income. I personally refuse to have any interaction with the US government and especially refuse to acknowledge that the SEC or FBI have any jurisdiction over me especially since I do not live nor do business in the USA. I also advocate boycotting the USA for vacation purposes and think twice if I have to buy their produce in the grocery stores.