>>89105
For T-bonds, it depends. You are helping the federal government finance its massive debt, which comes at the expense of taxpayers, but some would argue that as the government has already stolen quite a bit money from you, there's no moral travesty in taking money from the government until you've taken more than what's been stolen from you. I have no intention of purchasing T-bonds for a variety of reasons besides ethical so the question's never really come up for me.
For the checking account, I'd say that's like making the decision of whether or not to buy into what you think is a Ponzi scheme. It's less a question of ethical integrity and more a question of personal interest–if you know this thing you're paying into can't possibly last in the long-term, you should know that putting money into it means there's a chance you won't get it back. The bank and the Fed which enables its fraud are at fault here for deceiving your customers, not you.