Legal Question in Family Law in California

It depends on whether it is reasonably calculated to lead to the discovery of admissible evidence. If he can make any reasonable argument that your facebook account and phone records have the possibility of containing anything that could lead him to evidence in the divorce he will get it. You also need to bear in mind that spouses owe a fiduciary duty to each other, meaning you must put his interests at or above your own. Most judges consider this to include a duty to disclose pretty much anything the other spouse asks for, unless it is patently absurd.

He can subpoena your phone records. He can look at your facebook account without court intervention if you don't have him blocked in your facebook privacy settings.