https://www.engadget.com/2016/12/15/president-obama-signs-ticket-bot-bill-into-law/
It sounds like TicketMaster was pushing for this. Although they theoretically had their own policies, the only thing they could do was deny admission if they suspected a ticket was acquired via automated software.
I'm also thinking that a number of people looking to acquire tickets/reservations for themselves had used bot software.