Screen-scraping has always been a dubious practice and the trigger of many lawsuits. Many website owners, not surprisingly, jealously guard their content and are resentful of anyone who sends spiders to grab data and use it on their own site. They view screen-scrapers as necrotic vampires who steal users, siphon-off advertising revenue, and suck-up server and bandwidth resources without giving anything back. On the other side, screen scrapers have argued that if content providers don’t want to share their data, they should not put it in such a public place like the World Wide Web.
Amongst honest web developers, screen-scraping without prior approval is generally frowned upon. From a legal standpoint, depending on where you are, restrictions on screen-scraping usually fall into the realm of civil contract law through website Terms and Conditions clauses. Those who wish to screen-scrape should, first and foremost, get permission to do so. Otherwise, they should not...