Under normal circumstances, theft is prevented simply through the application and social acceptance of property law. Ownership is often indicated by means of visual marking (license plates, name tags). When clear owner identification is not possible and when there is a lack of social observance, people may be inclined to take possession of items to their own benefit at the expense of the original owner. Motive and opportunity are two enabling factors for theft. Given that motives for theft are varied and complex and are generally speaking not within the control of the victim, most methods of theft prevention rely on reducing opportunities for theft.
In addition to the initial obtainable cost of an item, the cost of replacement or recovery from theft of the item is usually considered when considering the cost of installing an anti-theft system. This cost estimation usually determines the maximum cost of the anti-theft system and the need to secure it. Expensive items will generally be secured with a higher cost anti-theft system, while low-cost items will generally be secured at a lower cost. Insurance companies will often mandate a minimum type of anti-theft system as part of the conditions for insurance.