They're breaking the law. Prosecution?
Civil Harassment
In general, civil harassment is abuse, threats of abuse, stalking, sexual assault, or serious harassment by someone you have not dated and do NOT have a close family relationship with, like a neighbor, a roommate, or a friend (that you have never dated). It is also civil harassment if the abuse is from a family member that is not included in the list under domestic violence. So, for example, if the abuse is from an uncle or aunt, a niece or nephew, or a cousin, it is considered civil harassment and NOT domestic violence.
The civil harassment laws say “harassment” is:
Unlawful violence, like assault or battery or stalking, OR
A credible threat of violence, AND
The violence or threats seriously scare, annoy, or harass someone and there is no valid reason for it.
“Credible threat of violence” means intentionally saying...
Read about the law in Code of Civil Procedure section 527.6External link icon.
https://www.courts.ca.gov/1258.htm