Data theft is one of the most dangerous threats for online businesses today. And site scraping tools have become the weapon of choice to perform data theft. From highly publicized scraping attacks on sites like Google, RyanAir, and EasyJet, to innumerable unpublished incidents, scraping has become a wide-spread menace.

Scraping attacks range from harmless data collection for personal research purposes to calculated, repeated data harvesting used to undercut competitor’s prices or to illicitly publish valuable information. Site scraping can undermine victims’ revenues and profits by siphoning off customers and reducing competitiveness. Unfortunately, site scrapers can be very difficult to differentiate from legitimate Web application users. This paper investigates various types of scraping attacks, site scraping tools, and effective techniques to detect and stop future attacks.