If you want to run the risk, be my guest. I for one would rather be safe than sorry.
It's almost the end of the year, which in the US means tax season is right around the corner. I cashed out a few BTC and took some money off the table. To me, it was all free money anyway. If I pay my taxes, then I am free and clear. If I don't they can come at me any time in the next 7 years if they feel like it. All they have to do is threaten Coinbase and they'll know if I paid or not.
Yes, taxes suck, but it's the law and is it really worth the risk???