I'm sure you computer nerds can find plenty of places online and are able to set up hidden files and bury them deep within your computer systems surrounded by umpteen fire walls to stash your cash. Plumbers are old fashioned and like to hide it with extensions, summer houses and holiday villas....
On a serious note I find all sides of the argument a bit hypocritical.... On the one hand you'll have politicians saying do as I say, rather do as I do. These people are always the ones with the wealth but they will be attacked for being immoral in their tax avoidance schemes, none of which is actually illegal. The attacks will generally come from the working / middle class of people. The same people who ask me time and time again that if they pay me in cash can we avoid the vat element of the bill. Which then puts me in an awkward situation, do I accept the job as cash and not declare it? If I declare it I'm still liable for the vat regardless of whether the customer paid it or not. Or do I stick to the law and lose the job?.... As I live in the real world I know what happens. If we can avoid paying a tax we all will, that's why we employ accountants to make sure that everything we can claim for is claimed for and we only pay the bare minimum that is owed. The amount of tax owed or rather that is avoided by the relevant groups of people be it 20% vat or 40% income tax does not give one group of people the the higher moral ground to criticize the other... after all we all want to avoid it if we can and we all will if we get the chance....