Basically the enormous burden of proof will have to fall on elected officials and legal experts with 20+ minimum experience practicing in the field to cite good cause as to how and why they should ban the currency, if they even can, how these regulation/criminal code changes will be executed/implemented and what to do with those U.S citizens that have a stake invested in bitcoin in which they have 0 probable cause to seize such as a commodity. Just sounds like even if it was illegal the burden of proof would be enormous to be able to convict beyond a reasonable doubt the use of bitcoin especially when people get better with security methods such as using tor and linux-based operating systems as well as the manner in which they browse (different cpus, thumb drives, changing IPs as well as using wireless that either doesnt belong to you or are public hot spots).
Legally speaking even IF the regulations were CLEARLY spelled out word for word the execution and interpretation of this law (indictment and conviction under a jury-trial giving the defense every legal opportunity awarded to him) is virtually impossible, even for a government as big and powerful as the U.S. Hell even China couldnt do this which is why ppl are finally putting real value and equity (or transferring should i say) into BTC... the foundation of the method of exchange, ledger and storage of such currency is just too sound and the security will only get BETTER over time.