Getting the benefit of a good or service without paying for it, not necessarily illegally. This may be possible because certain types of goods and services are actually hard to charge for--a firework display, for instance. Another way to look at this may be that the good or service has a positive externality. However, there can sometimes be a free-rider problem, if the number of people willing to pay for the good or service is not enough to cover the cost of providing it. In this case, the good or service might not be produced, even though it would be beneficial for the economy as a whole to have it. Public goods are often at risk of free riding; in their case, the problem can be overcome by financing the good by imposing a tax on the entire population.