It's still a consensus if you think that our laws are based on a consensus. If you disagree and think our laws are also not based on anyone's opinion, then I suppose currencies are not based on anyone's opinion either. Perhaps the government never asked you what laws should exist, and perhaps the consensus doesn't include everyone, only the consensus of those in power.

Sell me that bridge. Identify the bitcoins I've used. Perhaps you'll succeed in finding some, but I don't think you'll succeed in finding all.

Cash is taxable too. I've paid plenty of taxes when using bitcoins, and unlike many other bitcoiners, I actually think taxes are a great thing. I don't think bitcoins' near anonymity have anything to do with evading taxes, anymore than paying with cash at the grocery register is enabling me to avoid taxes.

I don't want to make any predictions for bitcoins. I don't know if they will be heavily regulated or not. But so far, it has been very convenient for me to have internet cash.