Students attempting to access grades, study materials and quizzes were met instead with a message from a hacking group on Thursday.

Reports of the issue began pouring in Thursday, May 7, for thousands of learning institutions.

A key education computer platform used by California State University campuses, UCLA and thousands of schools nationwide was back online Friday following a cyberattack, but access to the system was not immediately restored at some universities.

The electronic case filing system used by the federal judiciary has been breached in a sweeping cyber intrusion that is believed to have exposed sensitive court data across multiple U.S. states, according to two people with knowledge of the incident.