@BillRM,
You sure have a one-track mind about how consumers can hide from paying taxes, but a) most people are honest, b) most are scared of the government, c) the feds can implement legislation to reveal who's trading with bitcoins, and d) the government catches up with tax cheaters - sooner or later. That's been the trend, and will continue long after we're gone. Commerce doesn't happen in a vacuum - even with bitcoins. There's always a buyer and a seller. Anybody can become the squealer, because reporting tax cheats can be lucrative.