According to Cornell Law Edu:
1) a false statement purporting to be fact;
2) publication or communication of that statement to a third person;
3) fault amounting to at least negligence; and
4) damages or some harm caused to the person or entity who is the subject of the statement.
I find it interesting that when sharing the truth people tend to get extra sensitive. If you knew better you would do better.
According to Revision Legal:
Defamation is legally defined as a false statement that serves to damage the reputation of a business or individual. Slander and libel are under the umbrella of defamation.
In order to have a case for defamation, you have to prove that the statement is not true and that it specifically concerns yourself or your business. It also has to be published by a third party–like a website or blog.
You’ll have to show evidence that your company experienced significant damage because of the statement. This is one of the hardest things to prove in court.
Unfortunately, you can’t take legal action against someone who is actually telling the truth. If someone digs up your dark past and posts it online, you can’t sue them. The truth hurts.