Here is the "Liberty Dollar" coin:

Here is a Peace Dollar

http://en.wikipedia.org/wiki/Peace_Dollar
http://en.wikipedia.org/wiki/Dollar_coin_(United_States)
The issue is in many ways is this similar enough to the "Liberty Dollar" to confuse someone who has at best a limited knowledge of the coin.
If this '"Liberty Dollar" did not have the word "Liberty" in the same place as on the Peace Dollar, if it did not have "Trust in God" which is close to "In God We Trust" and a different design (not lady Liberty) the Coin could have survived. The problem was NOT that a coin was made, that the coin appeared to people like it had been issued by the US Government. That made the Liberty Dollar illegal, not that someone made a coin.
Remember under Federal Law it is legal to mint coins, as long as you do not try to use it as legal tender (You can do exchanges by barter, one coin for something else, but NOT use the coin as a dollar to buy something). The bit coin does NOT look like a US Coin, all it is is an exchange of these bits for something else, that is barter not use as
Furthermore, the Bit Coin can also be viewed as a Check. A Check is NOT legal tender, but can exchanged for something of value if both sides agree. As long as the bit coin is used either like a check or as an instrument of barter, it is legal. The "Liberty Dollar" appears to have wanted to go one step further, to be used as legal tender and that is illegal. Yes, this sounds like a technical difference, but it is the difference the Courts are looking for.
http://en.wikipedia.org/wiki/Liberty_Dollar