Well it's not scraping in itself that is good or bad. What matters is how you use the scraped data. It would be extremely unethical to steal data, republish it or use it to cause harm to a business. This was clearly established when the EU passed a judgment in favour of Ryanair.
The EU's highest court passed a judgment in favour of Ryan air, and this will positively prevent people from scraping and using others data in an unethical manner. Ryanair had claimed that PR Aviation scraped its data regarding the flight scheduled and then used it to allow people book Ryanair flights via the PR Aviation website and this is clearly an infringement of database rights. It was very clear after the judgment that if a website does not want its data to be scraped and used, it can set contractual restrictions that prohibit other companies to steal and use the data for their own vested purposes.
All the price comparisons websites will come under the radar now and will be restricted to use information only as per the commercial agreements with the online business and companies from whom data is extracted will be all empowered to restrict who will use their data and how!
The use of data scraping activities is hence a relatively grey area, and what makes it so is that some people just steal and post other people's data as their own, while others use it illegally for their own profit simultaneously leading to loss of the data owner company. It is not just the unauthorised users who have come under the radar; even the lawful users of databases owned by a business can be restricted from using the data in a way that conflicts with the interests of the owner company.
Data scrapers should understand and avoid activities that infringe upon the rights of data security. However one should not completely consider this activity and avoid using it completely. It is a valuable technology that helps when you are dealing with big data. It helps collect relevant information and use it to analyse trends and for business intelligence.
Most of the businesses do not understand how to extract and use information from the web legally and to gain profitable insights. Taking help of service providers who can manage big data deliver analytics and hence help you gain business insights, will open doors to a lot many opportunities and business growth.
Data scraping is an activity where you gain access to data that is not yours. And hence although there are several advantages to using screen scraping technology, a prudent approach where the technology is only used for purposes that do not directly involve reuse or republication of the data is the right way.