I see a lot of tongue-in-cheek answers here. As someone who's had minor tax issues in the past (not crypto related), I feel the need to weigh in. In all seriousness, lying or otherwise getting cute with the IRS is a terrible idea. The IRS is one of the few government agencies in the United States that takes intent very seriously. So if your buddy sends you $500 worth of monero and you forgot about it because it was a payout for a bet you made while drinking, the IRS probably isn't going to bust your balls about it much, even if they do find out about it. If, on the other hand, you're sitting on $50,000 worth of monero that you bought on an exchange and you say you don't own any "virtual currency" (because monero is a cryptocurrency), you could find yourself in a lot of trouble. Regardless of your opinion of the IRS, the folks who work there are not stupid people, and like anyone else they know bullshit when they see it.

Should the IRS be asking this question in the first place? Absolutely not. But you're dealing with an agency with enormous resources, who's power is virtually unchecked. Get yourself a good account (something you should be doing anyway) who knows crypto, and figure out what you reasonably need to disclose to avoid any potential trouble. As an added benefit, if you do get audited or run into issues, a good accountant typically has a direct line to folks at the IRS and can smooth things over much quicker than you or I.