One Year Into GDPR, Most Apps Still Harvest Data Without Permission
Protected Media is regularly approached by companies offering to sell data or social graphs. Greiner always makes a point of asking the salesperson how the data they’re peddling was obtained and what’s in it. “Invariably, they can never answer me,” Greiner said, “which leaves me to believe that they’re very rarely asked where they get the data from.”
See also: Websites not available in the European Union after GDPR—that's a long list.