A US Court of Appeals has ruled that a company's terms of service can be updated via email and that use of the service can imply consent to the new terms. The court's decision was based on a three-factor test, which considered whether the user had received notice of the updated terms. The ruling has sparked discussion about the effectiveness of email as a means of notification and the implications for consumer protection. The case highlights the complexities of electronic communication and the need for clear guidelines on notice and consent.