Damage to library collections, furnishings, or facilities that is intentional rather than accidental, usually motivated by anger or malice on the part of the perpetrator (see this example). Vandalism detracts from the physical appearance of a library and its resources. The cost of repair or replacement puts an unwelcome burden on the budget. To avoid detection, most acts of vandalism are committed in unstaffed locations or after hours. Some libraries employ a security guard to keep an eye on areas not visible from at least one public service point when the library is open. Compare with defacement.