An interesting article offers this short overview of the legal hurdles to bitcoin’s acceptance
Legal Issues – Needless to say there are serious risks on further growth of bitcoin on account of the uncertain legal status of bitcoin as a financial tender type. Some jurisdictions have deemed bitcoin to be a commodity whereas others treat it as currency. Some countries have outlawed bitcoin altogether and treat the possession of bitcoin as a criminal activity.
At the time of writing the United States treats bitcoin as a commodity. Any agency involved in the transfer of bitcoin with fiat currencies comes under the purview of banking and money laundering laws and requires licensing in every state, thus there is a high entry bar for exchange activities. For consumers, the act of purchasing a commodity in bitcoin is a taxable event. This treatment certainly hinders wider adoption.
Regulators clearly see the bitcoin features of anonymity, decentralization and lack of a central control as detrimental to control. However, it is fair to assume that a complete ban on bitcoin would continue to take place only in totalitarian jurisdictions. In western countries, it is unlikely for governments to impose a categorical ban on bitcoin. It is more likely that tax reporting, VAT, etc. would be based on some kind of honor system. There are some successful examples of parallel currencies that are recognized as legal tenders. An example is the WIR franc developed in Switzerland in 1934 and still in use at this time.
Tracking Global Law 