Sooo many issues with tainting. The people who are like "Oh, taint wouldn't be so bad... those libertardian anarchist bitcoin culters need to lighten up, it might actually be good, you know, to stop terrorism, money laundering, theft" I want to see the looks on their faces after a taint program is actually attempted and we see the many instances of error, corruption, and outright fraud, as well as the general confusion resultant from trying to implement the laws of single multiple jurisdictions upon a global currency... I imagine it will be the same as the looks on Obama voters' faces as they slowly realize what he is actually doing in office... I'm not overdramatacizing, these are legitimate issues which the pro-tainters haven't even begun to address. Which countries' laws are we talking about here? Will taiwanese businesses be prevented from accepting coins which have been used to break Taiwanese laws, but what if they are sent to Kazakhstan or the US? Will the governments of those countries have a treaty with Taiwan that specifies adding taint to those coins that have broken laws in other countries that are not on the books in the US? Or what about if a Colorado citizen receives coins for pot in a store (legal by Colorado law) but then sends those coins to a relative in Florida - then the coins are tainted after the relative receives them. Then does the relative need to pay $500 for an appeals process for a coin transfer that was worth $400? The red tape will be hilarious.
Perhaps one will need to hire a lawyer or pay a large fee to appeal fraudulent taint? Then there is an unrealistic burden on low-income folks with lower transfer amounts. If I make $1000 a month and I receive a $200 transfer from a relative which happens to be tainted because of some jurisdictional technicality, I can't afford the $100 appeals fee! No I'm sure all of this will go smoothly without any problems or corruption ;-)
translation: in aggregate, Bitcoin participants won't be able to afford validation; thus they will ignore it.