questions have arisen as to the extent to which a private owner of land can exclude certain persons from land which is used for public purposes, such as a shopping mall or a park. There is also a rule of law that a landowner whose property has no public access can be awarded an easement to cross private land if necessary to reach his own property. Conversely, public nuisance laws prevent alternate use of public streets designated for public transit from being used for block parties and playing basketball. Parents or other legal guardians are typically able to restrict the movements of minor children under their care, and of other adults who have been legally deemed incompetent to govern their own movement. Employers may legally set some restrictions on the movements of employees, and terminate employment if those restrictions are breached. Domestic restrictions Governments may generally sharply restrict the freedom of movement of persons who have been convicted of crimes, most conspicuously in the context of imprisonment. Restrictions may also be placed on convicted criminals who are on probation or have been released on parole. Persons who have been charged with crimes and have been released on bail may also be prohibited from traveling. A material witness may also be denied the right to travel. Though travelling to and from countries is generally permitted (with some limitations), most governments restrict the length of time that temporary visitors may stay in the country. This can be dependent on country of citizenship and country travelled to among other factors. In some instances (such as those of refugees who are at risk of immediate bodily harm on return to their country or those seeking asylum), indefinite stay may be allowed on humanitarian grounds, but in most other cases, stay is generally limited. One notable exception to this is the free movement of people in the European Union, where citizens of any country in the EU and EFTA generally enjoy indefinite stay in other EU/EFTA countries. Furthermore, restrictions on the right to relocate or live in certain areas of a country have been imposed in several countries, most prominently China. In a child custody dispute, a court may place restrictions on the movement of a minor child, thereby restricting the ability of the parents of that child to travel with their child. Entrance restrictions in certain countries The Visa Restrictions Index ranks countries based