 Some theorists, such as Hayek (1960), argue that it can be permissible for people to be forced to pay for basic police services. But this argument seems problematic within libertarian theory. If people do not agree to their legitimate possessions being used for these purposes, it would be unjust to force them to pay for these services, even if they clearly benefit as a result. After all, libertarians generally deny that merely receiving a benefit suffices to justify enforceable requirements to pay.