How about if the income is in your country of origin? Can't your side project just pay out where ever you're from? It's the Internet, websites aren't really located anywhere.
You could just ignore this, like I do, but if you're in America on an H1B visa, which I'm not, then you're probably best off following the rules, lest they expel you and never let you back in, without giving you time to organise getting all your stuff back first.