The legality may also depend on the type of data being collected. For example, it is likely safer to scrape Yelp to gather public facts like business locations

The legality may also depend on the type of data being collected. For example, it is likely safer to scrape Yelp to gather public facts like business locations and phone numbers versus if the data is "copyrightable" like customer reviews. Both, however, would violate Yelp's TOS. See: http://streetfightmag.com/2013/03/04/legal-battles-erupt-over-data-mining-of-hyperlocal-data-heres-how-to-protect-yours/ http://streetfightmag.com/2013/03/04/legal-battles-erupt-ove...