Register.com, Inc. (Register) (plaintiff) was a registrar for the issuance of internet domain names. In compliance with federal agency regulations, Register updated and made available to the public all registrants’ contact information. The results were accompanied by a restrictive caption written by Register that prohibited searchers from using the data to “support the transmission of mass unsolicited, commercial advertising or solicitation via email.” Verio, Inc. (defendant), a web site development business, created an automated software program that submitted multiple successive queries each day to acquire the contact information of new registrants. Verio sent these registrants marketing solicitations by e-mail, phone, and direct mail. Register updated its caption to further bar mass solicitation via direct mail or telephone, in addition to e-mail. Verio accordingly stopped using the information for email marketing but refused to cease marketing by direct mail and telephone. Verio arguing that it never received legally enforceable notice of the new restrictions. The district court enjoined Verio from using the contact information. Verio appealed.