Scraper bots steal data from online sources. This is commonly seen in verticals such as data aggregators and other providers which gather or generate data and content, and then sell access to it. Scraping is obviously a direct threat to these business models. 

Elsewhere, scraping can cause indirect damage. For example, retail sites contain prices and other product data which, when stolen, can destroy a competitive advantage. 

Sophisticated scraper bots can eventually steal entire databases, even when they aren’t directly available to users of the targeted site or application. This can be done through repeated queries or requests, using different parameters each time. For example, insurance companies provide rate quotes for specific combinations of input criteria. A scraper bot can submit continual requests for quotes, with a different combination of criteria each time, and capture the quotes that are returned. Eventually, the complete database of rates can be obtained.

Scraping and data theft can degrade search engine rankings, damage reputation among users, and decrease the user base.