Without Authorization?
You commit trespass to chattels if you (1) intentionally use someone’s personal property (2) without authorization and (3) thereby impair the value of the property or harm an interest relevantly related to the property.
When CompuServe connected its email system to the Internet, it did not password protect the system, or restrict access to it by the general public in any other way. Anyone could send an email to CompuServe’s clients.
Therefore, by opening its email system to the general public, CompuServe consented to access to its email system by the general public.