If the money is in your bitcoin wallet, then the government has the same access to it as if the money were paper dollars hidden under your mattress. Coercion is available, but they cannot take it directly.
If your money is in a (regulated) bitcoin exchange, then the government has more-or-less the same access to it as if it were in a bank. The serve a court order to the third party you have entrusted with your money, and the third party complies, without your direct involvement.
Many of the arguments about bitcoin involve comparing apples to oranges. Bitcoin is a currency, its direct comparison is dollar bills, but most of the problems that it purports to solve are aspects of banks not dollars. There is some argument to be made that you can do more with Bitcoins without involving a bank, but I see a lot of people putting Bitcoins in banks (or exchanges or other regulatable third parties), and a comparison of Bitcoin + surrounding financial institutions vs Dollars + surrounding financial institutions is not as favorable to Bitcoin.
If your money is in a (regulated) bitcoin exchange, then the government has more-or-less the same access to it as if it were in a bank. The serve a court order to the third party you have entrusted with your money, and the third party complies, without your direct involvement.
Many of the arguments about bitcoin involve comparing apples to oranges. Bitcoin is a currency, its direct comparison is dollar bills, but most of the problems that it purports to solve are aspects of banks not dollars. There is some argument to be made that you can do more with Bitcoins without involving a bank, but I see a lot of people putting Bitcoins in banks (or exchanges or other regulatable third parties), and a comparison of Bitcoin + surrounding financial institutions vs Dollars + surrounding financial institutions is not as favorable to Bitcoin.