Everywhere around the globe (save for a few special nations like Brunei) you'll have to organise and pay your tax at some point and along the way this will mean notifying the government of what you're earning.
Even when you work an online-based business -- where in a lot of cases your earnings will be deposited right into your account -- it's very easy for the government not to pick up on this, unless you get audited down the road.
I've been working online for around 7 years now and in that time I've met countless people who are not only not paying tax while operating a home-based business, but are actually proud of the fact they're not paying tax at all. While this may sound great to some, this can be a dangerous act.
The thing is that if you -- or anyone else dodging tax -- is caught, severe punishments can be dealt to you, which may include imprisonment in many nations.
It's becasue of this that declaring your tax and paying it on time is extremely important. Sure you may be short of between 8%-60% of your money (depending on where in the world you live), though just ask yourself if the penalty of losing your freedom is really worth those extra dollars.
The great thing is that you can reduce your tax in most nations by doing things like claiming more back, making sure you have a great accountant doing your tax or even moving to a lower-taxed country, which is even something I've done personally. While this may seem like a big step, I'd still rather do this than try and break the law.
Whatever you decide, in the end nobody has this choice apart from you. Though if you do read this then still get caught, don't say you haven't been warned!