This concept of maintaining fungibility is not a new one in bitcoin, and of course, it is going to be tested, and perhaps tested with a bit of rigor.  Just because it is a potential vulnerable area does not mean that bitcoin is not going to be able to overcome various attacks on its fungibility.  Should we not be taking one step at a time, rather than assuming that various attack vectors are going to be successful merely because people, such as jbreher, are attempting to spread FUD about it?

Surely, I might conclude that fungibility is a .1% concern, and you might conclude it is 10% and jbreher might consider that it is 20%, but the mere fact that we have different probabilities about future value and utility should cause us to invest differently based on how BIG we believe the threat to be.  Some folks are going to be closer to being correct than others, and that is the nature of the free market, to some extent.


Your answer above, about fiat being sort of non-fungible seems to be a bit off.   Fiat is backed by government laws, etc, and there have been fungibility court rulings in regard to fiat.  Of course, governments can chose to change their fiat related rules too.  I would conclude that there is a decently strong public policy to attempt to maintain dollar fungibility and that gives the dollar decent strength and decent predictability.  Of course, the rules could be changed, at some point in regards to the dollar.  Seems to be a bit more difficult to change the rules in regards to bitcoin, and in that regard, there will likely be both governmental attempts or anti-bitcoin groups that try to change bitcoin rules, and some of the anti-bitcoin groups will actually tout themselves as being pro bitcoin, and out to do what is "best" for bitcoin.  Good luck, we will see, and each of us will decide if we are scared by what is happening or decide to sell our bitcoin (or discontinue usage of bitcoin) based on such happenings.


You are likely correct that there is a sliding scale when it comes to fungibility, and I think that most free market types are going to perceive the most value in bitcoin being associated with greater levels of fungibility... so yeah, you are right that lesser fungibility may maintain some value, but the amount of decrease in value may be a lot greater than what you seem to be projecting it to be.  For example if confidence is lost because coins get blacklisted, then surely that seems problematic to me if it is allowed to occur.  So if any 3rd party such as coinbase or fed government tries to label coins, then there would likely be some effort by the bitcoin community to either not use their services or to move coins to other location and clean them of their blacklisting.