In some cases, charging interest (usually at high or usurious rates) on money or property lended causes problems. Most economists attribute the shift from credit being available on only usuorious terms of interest to the modern banking system first established in Holland in the 15th Century as the cause of the shift from wildly fluctuating prices from season to season (up and down) to gradual and persistent inflation. Moderate inflation produces the incentive to invest in productive enterprises, rather than hoarding wealth, which was one necessary step in the economic revolution which brought about the industrial and agricultural revolutions.
An economy based on fraud and usury is on a slippery slope to financial ruin for that entire economy, and SecondLife was headed that way, as Albania did with the collapse of fraudulent schemes in the early nineties in the real world.
There is an interesting philospophical debate on whether investing to recover the time cost of money is prohibited by Judaeo-Christian religions or whether the ban is on usury as we would today understand it.