Public property is highly respected and preserved in Islam. Clear and severe warnings are found in the Qur’an and the Sunnah concerning any violation — no matter how little it may seem — against public interests or utilities.

Answering this question, Sheikh Muhammad ibn Al-`Uthaymeen, a prominent Saudi scholar, said,

Using government cars or any other equipment that belongs to the state, such as photocopiers, printers, etc., for personal purposes is not permissible, because you have to use these things for the public interest. If a person uses them for his or her own personal needs, this is a kind of violation against all people.

If something belongs to all Muslims, it is not permissible for one person to use it for him- or herself. The evidence for that is that Prophet Muhammad (peace and blessings be upon him) forbade ghulul (a person taking something from the war booty for him- or herself), because this [the war-booty] is public property.

If one sees people using government equipment or cars for their own purposes, he or she should advise them and explain to them that this is haram (prohibited by Allah). If Allah guides them, then this is the desired outcome; if not, then one should report the case, because such reporting would be a kind of cooperating in piety and righteousness. The Prophet (peace and blessings be upon him) said, “Support your brother whether he is wrongful or wronged.” They [the attending Companions] said, O Messenger of Allah, we know how to help him if he is wronged, but how can we help him if he is wrongful? The Prophet said, “Prevent him from doing wrong; that is how you can help him.” (Al-Bukhari).