Family dispute

There is a newly wedded couple.The husband is hacking the data(conversations of past 8 years) of mobile phone of his wife. I understand that wife has some past(she had a very close friend with whom she mostly had a conversation on mobile) but she has move forward and left all those things after marriage(that is , she has stopped taking to that guy after marriage). The husband is threatening wife to expose the wife for her past which she has already forgotten and move ahead in life. Logically husband should not at all be concerned with the past of the wife where no relation exist between hsuband and wife at that time since everyone has its own freedom. The wife has also left job due to this under pressure from the husband and she might go to depression if these things continue. I want to understand about the laws and legal action to be taken against the husband who is hacking the data(conversation on mobile before marriage to which she has put an halt to that). My email id - [deleted]