Law & Order Special Victims once had an episode about a famous popstar having a paradise for kids at his mansion. He was falsely accused by golddiggers, later new accusations surfaced. A search lead to a secret room that made everyone wonder, but they couldn't make the case...
The star happened to be a bit strange and somewhat pale.
I don't remember the name of this character: it wasn't the name of an existing popstar and the episode ended just like always: the coicidence disclaimer:
"all events and charaters are fiction, any resemblance to real persons and event are coincidence...." (or something like that)
So, I guess it is about the way you present it.
If you are doing journalism/documentary and you can proof what you say you can use real events... that is like newsgathering, but I guess there has to be a greater good involved:
Nixon could be exposed (Watergate), but your neighbours' strange but legal bedroom hobbies are protected by privacy laws.
Lying about someone and damaging his/her reputation is always illegal.
Anyway:
for real legal advice go to a lawyer, not to IT.