Aetna and KCC began pointing fingers at one another nearly a year ago in private negotiations over blame for the disastrous mailings. Their talks culminated in tit-for-tat complaints in February. Aetna sued KCC in Philadelphia. KCC fired back the next day in federal court in Los Angeles, claiming that Aetna and its lawyers at Gibson Dunn had approved both the "form and content" of the notification letters before they went out. KCC also alleged that Aetna breached patient confidentiality rules when it gave unencrypted client data to the claims administrator without obtaining a protective order.