Tax evasion? Crime?

I've been thinking about that coffee shop that could charge people in Steemdollars for a cup of coffee. That means that they basicly are giving away free coffee, hurting their business, while at the same time stuffing their own pockets with money that the government will never be able to trace.
http://i.imgur.com/3BcwTu2.jpg
(you would never have guessed it, but I actually made this pic)

And even though this is ofcourse something that anarchists like, it could constitute a federal crime. Just as if you were pocketing cash money in your pocket instead of steemdollars.

So how are we going to treat this? Are we all criminals that deserve to be locked up? Or is it only when someone involves their 'normal' business with steemdollars that things get dicy?