The great world amusement center , a six-story complex packed with marriage brokers , magicians , earwax extractors , love-letter writers and casinos , was a favorite target of missionaries .
A webrobot is a program that processes the content found through a link , a webrobot can be used for indexing a page or extracting useful information based on a predefined query , common examples are - link checkers , e-mail address extractors , multimedia extractors and update watchers .