Well, I can appreciate people's concern... but it seems to me there are some dependencies here.
First depends on the tax authorities of any Steemian's country of residence. How does the IRS (for example) classify cryptocurrencies? As I recall, they don't give Bitcoin "currency" status, it's actually an "asset class."
That being true, UNTIL you actually "have dollars in your hand" all you technically have is what's called an "unrealized gain." Now, when you DO get actual fiat, there are two kinds of income. If you originally used dollars to INVEST in Steem, you end up with a capital gain. You get to subtract your original cost from your gross receipts and pay a somewhat reduced tax rate on the difference. Anything you were PAID for authoring/curating will probably be considered "ordinary income" BUT... you're not an "employee," you're an "independent contractor," so you'd probably have to complete a Schedule C if you're in the US.
By all means, run it by a tax attorney. Alternately... if you actually receive your earnings as ATM withdrawals on a largely anonymous BTC debit card? You have to figure out your own formula for sleeping well at night!
Hi, I'm late to the party, but it is never to late for me to address my favorite topic. I believe, assuming Steemit user is a US citizen - when the Steem currency (any of the three but there is some debate on Steem Power) is credited to his/her account for posting/curating, it is treated as property they received and is taxable at that point in time). See Notice 2014-21 Q-3, 5,10. He/She will then begin a holding period and if they convert to USD after a year, will be taxed long-term capital gains (or a loss) on the difference between the USD proceeds and the value when he/she received the crypto. The good news is, he/she may have also potential expenses that are now business expenses. This will be the subject of one of the many topics I am covering in my tax blog, and I am going to have examples and helpful suggestions for the filing season that is upcoming.
PS: I will research whether it is appropriate to classify the Steem Power as restricted property, or that it falls outside scope of cryptocurrency from the perspective of the Notice, but I will have more in depth analysis later on.
This is not tax advice to any one individual and shouldn't be used to attempt to avoid taxes/penalties.