Blake Lively has asked the judge presiding over her lawsuit against her It Ends With Us co-star Justin Baldoni to strengthen the case’s protective order on confidential filings, citing “violent, profane, sexist, and threatening communications” she’s received since the suit was filed.

In a letter submitted Thursday night and reviewed by Rolling Stone, Lively and her husband Ryan Reynolds asked to modify the existing protective order by adding a “For Attorney’s Eyes Only” category that would help protect certain documents “of such a highly confidential and personal,...