Nowadays the rate at which bloggers and social media users defame people on the internet is quite alarming and disturbing.
Sometimes you would wonder if at all the person behind that post has conscience to write such derogatory and hate speeches against their fellow humans.
I totally agree with you on determining the weight of the slander if it has a huge effect on your person, brand, source of income, family etc then a lawsuit will be the best tool to implore to deal with such persons.