What he would be doing would be committing the crime of "harassment" electronically.
Now this makes for interesting reading:
http://pcw.gov.ph/focus-areas/violence-against-women/definition
What is VAW?
The UN Declaration on the Elimination of Violence against Women (1993) defines violence against women (VAW) as, “any act of gender‑based violence that results in, or is likely to result  in, physical, sexual or psychological harm or suffering to women, including threats of such acts, coercion or arbitrary deprivation of liberty, whether occurring in public and private life. Gender-based violence is any violence inflicted on women because of their sex.â€
The Philippine definition as contained in Republic Act 9262 (Anti-Violence Against Women and Their Children Act of 2004) states VAW as "any act or a series of acts committed by any person against a woman who is his wife, former wife, or against a woman with whom the person has or had a sexual or dating relationship, or with whom he has a common child, or against her child whether legitimate or illegitimate, within or without the family abode, which result in or is likely to result in physical, sexual, psychological harm or suffering, or economic abuse including threats of such acts, battery, assault, coercion, harassment or arbitrary deprivation of liberty.
It includes, but is not limited to, the following acts:
  "Physical violence" refers to acts that include bodily or physical harm;
  "Sexual violence" refers to an act which is sexual in nature, committed against a woman or her child. It includes, but is not limited to:
    rape, sexual harassment, acts of lasciviousness, treating a woman or her child as a sex object, making demeaning and sexually suggestive remarks, physically attacking the sexual parts of the victim’s body, forcing her/him to watch obscene publications and indecent shows or forcing the woman or her child to do indecent acts and/or make films thereof, forcing the wife and mistress/lover to live in the conjugal home or sleep together in the same room with the abuser;
acts causing or attempting to cause the victim to engage in any sexual activity by force, threat of force, physical or other harm or threat of physical or other harm or coercion;
prostituting the woman or her child.
"Psychological violence" refers to acts or omissions causing or likely to cause mental or emotional suffering of the victim such as but not limited to intimidation, harassment, stalking, damage to property, public ridicule or humiliation