We now face a conundrum regarding the Constitutionality of not only the US dollar but also the ever-encroaching virtual currencies like the Bitcoin and other virtual type currencies. Since 1934 when Congress amended Section 16 of the Federal Reserve Act, the US dollar has been subject to governmental intrusion in the financial sector.
The main worry right now is that the US dollar is just fiat money, just like bitcoins and other digital currencies, which are also backed by who knows good faith and credit. Then there are the banks' transfer systems, which are the conduits for interbank money transfers, but oftentimes, whoever controls them can intercept, shift money into other accounts, hold on to it earning interest, or prevent you from transferring it.
The Federal Reserve Act was passed in 1913 by Congress without having the constitutional authority to do so, so when we put all of this together the US dollar is now devoid of any unilateral backing and is therefore unconstitutional by acts of Congress. In other words, congress has taken it upon themselves to amend and pass legislation that clearly circumvents the intent of our founding and our Constitution.
What Congress has done over the years has resulted in the creation of smoke and mirrors financial institutions, all of which have contributed to the greatest wealth disparity gap in history, the largest national debt in history, and a number of depression-type economic catastrophes. This has led to the sobering realization that many aspects of our current financial crisis could have been avoided had Congress acted in good faith by abiding by the Constitution."""