Define robbery. Taking the US as an illustrative example: How about legalising corruption in politics through Citizens United and having laws systemically rewritten to favor the rich? Or the government subsequently effectively pumping investors portfolios with the poor's money through QE (especially using the slap in the face "too big to fall" justification which essentially says the wealthy are more important to the economy than the poor)? How about raising taxes on the poor by not adjusting tax brackets for inflation while corporate taxes have trended down? How about Exxon making record profits by getting government subsidies and further subsidising its own profits by making the world poorer with its pollution?

Paying taxes is not a voluntary choice. Subjecting yourself to inflation is not a voluntary choice. Having your environment polluted is not a voluntary choice. You have no political alternative to this system, no vote you can make to say no to it. The rich taking from the poor is only not considered robbery since the wealthy both (legally) bribe the lawmakers and are the lawmakers. Just look at Clarence Thomas. Only the poor taking from the rich is robbery.

The semantics of what constitutes robbery aside, the world is experiencing a totally unsustainable concentration of wealth which will eventually cause markets for goods & services, consumerism, and the engine of world economics to collapse toppling the entire wealth pyramid. On top of that, global warming and the fact that oil supply seems to be plateauing (So we can't kick the true costs of energy down the road again) is suddenly going to make being poor much more expensive. At some point sheer practicality will prevail and redistribution to the poor will need to happen, and if it doesn't happen voluntarily, it is likely to result in an eventual revolution. If a revolution happens, it's likely that suddenly lawmakers will change the semantic definition of robbery.