Andrew Auernheimer, more commonly known as weev, got all of AT&T's ipad users' email addresses at that time, by enumerating all the possible sim-card IDs, against a public facing ATT website. He was charged and convicted the Computer Fraud and Abuse Act (CFAA), and sentenced to 41 months in federal prison that. His sentence was vacated after 13 months due to a technicality of the venue; that judge did not address the substantive question on the legality of the site access.
Weev may be an odious person, but everyone has rights in a court of law, even white supremacists.