The lawsuit follows Lively's complaint about publicity tactics employed in the release of movie "It Ends With Us."

Amber Heard says she has seen "first-hand" the online abuse and smear tactics that Blake Lively has endured in her ongoing feud with "It Ends With Us" co-star and director Justin Baldoni, who's accused of sexual harassment and other unwanted behavior on the film.

Blake Lively has sued Justin Baldoni, accusing him of sexual harassment and attempting to destroy her reputation. The director has hired the same PR expert that Johnny Depp used during his legal battle with his ex-wife,