How Can I Protect Myself from Envious and Greedy People?

A friend asks:
There are some people among our close relatives who are malicious and, unfortunately, behave disgracefully. They stir up those around them to satisfy their excessive demands. They previously took the matter to the legal authorities, but were unable to get their way and were found at fault. Now, through anger, violence, insults, and threats against other family members—and by carrying out those threats—they are trying to intimidate the devout members of the family and damage their reputations. (In fact, perhaps they have received twenty times as much material support and kindness as the other family members.) Yet they continue to cause trouble and distress the family. Please advise us on how to protect ourselves from these envious people.