Free riders are commonly inadvertent recipients of a socially-provided public good for which they have made no contribution.
A public good consists of resources, goods, or services that available for public consumption. Curiously, the use of public good by any individual or group does not shrink its availability nor inhibit its consumption or use by others, e.g. radio broadcasts and street lights.
The ‘free rider problem’ is a situation where the free riders who benefit from free riding do so unreasonably and the probability of forcing the free riders to make a contribution and thus consume the public good rightfully.