Maybe they should consider illegal confiscation of bank accounts, since bank accounts are virtual nowadays

first off im not sure how one can 'confiscate' an account, perhaps you meant something more along the lines of freezing someone's assets? this is just a guess, but in that case, i think in legal terms, there is a difference between what bitcoin is classified as, versus the legal tender of a nation as deemed by the government (which is contained in a bank account).
"[it is]not appropriate to confiscate Bitcoins as they cannot assume an objective standard value.
in this case, the korean won, the legal tender of the republic of korea, does indeed hold an objective value.
They are right. But sooner or later it will be misused by criminals, and the whole finantial system is based on virtual stuff that doesn't even exist. Banks can create money out of nothing and lend it.
bitcoin has already been used in such a manner by criminals, namely silk road and other marketplaces would be the first thing that comes to mind.