The Economist posts a fascinating story about Ikea's corporate structure. I don't see anything immoral in the way that Ikea's founder and stakeholders have sought to maximize, among other things, their tax efficiency. Nor did I see anything wrong with
U2 moving to Amsterdam a few years back. But I do think these examples give us an insight into the nature of taxes in general. Rational, reasonably intelligent people will seek to minimize their tax bills. The more complicated a tax code becomes, the more convoluted rational people's activities will become to accomplish their goals.
Government should use taxes like armed citizens use their guns: only as an absolute last resort.