What are the options of stopping bitcoin? It could be banned from paypal and card transactions. But you can't really ban it otherwise. If I want to give you something for bitcoins, we can do the exchange. There's no real trail, so it simply can't be stopped for personal use.
What value are bitcoins if nobody can legally accept or use them? The IRS is not known for being understanding toward things that look like tax evasion.
Multiple identities make this almost impossible to track. You can have a separate wallet for every transaction and then pass the bitcoins through http://doubletrouble.bitcoinbet.com/ if you want to be paranoid. If you verify your bitcoin history, you should be pretty safe from IRS-like companies.
Wasn't this the whole purpose of the distributed system? It was created with such situations in mind where a governments and others try to stop the flow of money through certain areas or to individuals.
