Think about it...how did they get Al Capone? Was it for murder? racketeering? loan sharking? etc... Nope, he spent forever in a Federal prison for tax evasion. The way to avoid the same for someone on this board is to set-up a LLC, post all income through the LLC, pay yourself a weekly, bi-weekly, or monthly pay check for consulting services. Also pay the LLC taxes and your personal taxes.
Now you have a legitimate source of income that you can produce via LLC paycheck stubs to get loans (car, house, etc.), claim a legitimate tax return (so you avoid the Al Capone issue), and also head off some LE issues... When you claim your time is for this or that and the LLC supports it your risk goes down. Your credit history improves and you are a solid tax paying citizen.
Think about it from the same point of view that many use to promote legal, taxable use of marijuana, etc... If you say you are doing one thing, be upfront and honest about the income from it. Who's to argue if an extra 40 per visit doesn't get posted as long as it doesn't lead to a lifestyle beyond what's report (as was discussed here?). LLC's are so cheap to set-up and the deductions OY Vay....