Even you dont want to pay tax and so many reason in your mind to tell to police. they can know that your lying because on the last part you cryptocurrency will go to bank and can detect where your money comes from and this will give you a lot to explain and in the last part you will be caught for not paying taxes much better to pay it because in the end you will suffer on the consequences.
well, maybe this will apply when the government has given regulations regarding this matter. however, as long as there are no rules regarding taxes to be paid from bitcoin, or altcoin users, I think it's natural that we don't pay them. moreover we do not know what the tax is for.