Unlike the types of physical and electronic forms of money that we've seen historically, Bitcoin is significicantly different.

When I pay cash I am physically transferring currency and/or coin from me to you.  When I pay with a credit card, I am contracting with a third party to send funds (less a fee) to the recipient.

But when making a bitcoin payment from my own wallet, the first step is that I have my Bitcoin client software create some data.  In the U.S., this is protected speech under the First Ammendment.  However to work as money, I must broadcast that data to nodes that I am peered with which will cause the data to get included in the block chain.

Creating the data for that transaction is protected as a right but using it as money doesn't mean that it is immune from other laws.

There are scenarios where let's say I had created a painting (which is another expression of free speech) and sold it but engaged in money laundering to disguise the source of the funds, I would likely be violating AML laws.