A common question that crops up in the various Facebook writing groups I belong to tends to center on using real people, companies, quotes, or products in a book. The following link addresses using real people in your writing: http://helensedwick.com/how-to-use-real-people-in-your-writing/. I would include one additional caution to the link: just because you don’t think your use violates this rule doesn’t mean the person or company will agree with your viewpoint. A good example could be where you meant the usage to be neutral or positive, but you write it in such a way that it could be taken in a negative way.
First, a simple rule. If what you write about a person is positive or even neutral, then you don’t have defamation or privacy issues.
You also need to be careful when dealing with facts since too often these days opinions are presented as facts. I photographed a triple headstone years ago (father and his children), all with the same death year. In researching the names, I discovered they were victims of a triple homicide. The police arrested somebody and the defendant was found not guilty. In the first jury meeting, only two of the jurors felt the defendant was guilty. There were too many unanswered questions and a lack of other supporting evidence the person had killed them. Yet, a police officer involved with the case lamented the fact they had chosen the wrong jury. In my opinion, the defendant exercised some very poor judgment in a number of ways and may have crossed the line by not reporting something the defendant heard, but I don’t believe the defendant was part of the murders.
The above applies to companies and products. I am going to use my favorite go to ethnic group – Martians. I don’t believe there are Martians, but on the off-chance Martians exist and declare war on Earth because I use them, consider this my standing apology for the death and devastation caused by such a war. If I accused the Martians of your favorite stereotype (whatever it may be), I am probably safe from getting sued. Although I could see somebody pretending to be a Martian to file a lawsuit as opposed to an actual Martian. Hopefully, my attorney would be able to prove the person wasn’t Martian. Maybe I badmouth the Martian Acme Corporation’s Martian frozen ice dessert. Let’s suppose in either of these cases, I use enough clues that it’s obvious I am talking about a specific group, individual, or product made on this planet. It’s possible I could be successfully sued for any number of the issues in the above link in Helen’s article.
Let’s move on to dead famous people. In general, you may be able to get away with a lot when it comes to a famous dead person as many of their rights end when they die, but that doesn’t mean you should. Also, some of their rights may continue after death. Contrary to many in Facebook groups who seem to think the dead are fair game, I tend to take the cautious route. Let’s take Elvis, a perennial favorite. FYI: I believe he’s dead (putting that out there in case somebody thinks I’m in the Elvis is alive camp and hiding out with whatever favorite conspiracy theory group you like). There are enough diehard fans of Elvis that painting him in a bad light is a good way to alienate potential readers and future fans of your books, blog, etc. In my opinion, the risk of alienating future customers outweighs whatever shock value I may gain. A point made in Helen’s article involves getting permission from the individual or their estate. For example, if I wanted to use Lord of the Rings (LotR) or something related to J. R. R. Tolkien, I would contact his estate and see about getting permission. From what I have read, it probably isn’t going to be easy to get it and may cost more than I am willing to pay. It reportedly has a reputation about enforcing copyright on all things related to LotR and Tolkien.
A good rule of thumb is to avoid using real-world individuals (dead – especially if they have died in the last 40 – 75 years or living), companies, or products. A point made in one blog I follow is to use tissue as opposed to the brand-name of a popular brand of tissue even though most people would know what I meant if I used the brand-name. Some companies have no problem suing to keep the brand-name separate from the product itself. To throw a political monkey wrench in the system, badmouthing a politician (no matter how much you think they deserve it) often backfires.
To add another monkey wrench, there is such a thing as bad publicity. One of the mantras I see on Facebook and other social media is “There is no such thing as bad publicity.” I would use some great examples, but I would wind up banned from one of my favorite eating establishments and probably getting sued by individuals or companies in other cases. Simply type in bad publicity examples in your favorite search engine browser and you will find tons of great examples of companies that found out the hard way there is such a thing as bad publicity.