I don't like the way this article, and many others like it, disregard peoples ability to be malicious. They portray all humans as good-natured, kind and helpful

I don't like the way this article, and many others like it, disregard peoples ability to be malicious. They portray all humans as good-natured, kind and helpful, and while this is true for the overwhelming majority, the small percentage to who this does not apply do exist. I personally would love to read some good advice on how to deal with people who actively try to harm you, as most advice available focusses on how to make friends and acquaintances.