1. A method performed by a computer system, the method comprising: identifying, by the computer system, two or more documents; determining that a first identified document, of the two or more documents, includes one or more links that lead to scumware; determining that a second identified document, of the two or more documents, includes scumware; storing, by the computer system, and in a document index that relates search query terms to documents, first data indicating that the first identified document includes one or more links that lead to scumware; storing, by the computer system and in the document index, second data indicating that the second identified document includes scumware; providing, by the computer system and for display, a link to the first identified document, a link to the second identified document, a first indication that is based on the first data and indicates that the first identified document includes one or more links that lead to scumware, and a second indication that is based on the second data and indicates that the second identified document includes scumware, where the first indication is different than the second indication; receiving, by the computer system, a request from a toolbar, associated with a client device, for scumware-related information associated with the first identified document; and providing, by the computer system and in response to receiving the request, the first data, where the toolbar displays, based on the first data, a visual indicator of a shortest number of links from the first identified document to another document associated with scumware, where the number is more than one.