I am not a lawyer, but I can provide you with some general information to help you understand the issue. Using copyrighted material like TV show scripts in your ebook without permission could potentially infringe on the copyright holder's rights. In the case of Seinfeld, The Office, The Simpsons, and other TV shows, the scripts are most likely protected by copyright.

Creating an ebook teaching C++ using TV show scripts may fall under copyright infringement if you do not obtain permission from the copyright holders to use their works. Copyright law protects original works of authorship, which includes TV show scripts, and grants the copyright holder exclusive rights to reproduce, distribute, perform, and create derivative works.

There might be exceptions under "fair use" provisions in copyright law, which allow the limited use of copyrighted material for certain purposes such as teaching, research, and commentary. However, whether your specific use would qualify as fair use depends on a number of factors, including the purpose and character of the use, the nature of the copyrighted work, the amount and substantiality of the portion used, and the effect of the use on the potential market for or value of the copyrighted work.

To minimize the risk of copyright infringement, you should consider seeking permission from the copyright holders before using their scripts in your ebook. Alternatively, you could create your own original content to teach C++ or use material that is in the public domain or licensed under a Creative Commons license.

You should consult with a legal professional to get a more accurate assessment of your specific situation and any potential legal risks.

Reusing copyrighted characters from TV shows, movies, or other media in your own work can still potentially infringe on the copyright holder's rights. Characters are considered a protected element of a copyrighted work, and copyright law grants the copyright holder exclusive rights to create derivative works based on those characters.

While you may write your own scripts, using well-known characters from TV shows like Seinfeld, The Office, The Simpsons, and others could still be considered a derivative work, even if the storylines are entirely different. Derivative works based on copyrighted material usually require permission from the copyright holder to be legally created and distributed.

As mentioned earlier, there might be exceptions under "fair use" provisions in copyright law, but whether your specific use would qualify as fair use would depend on various factors.

To minimize the risk of copyright infringement, you should consider seeking permission from the copyright holders to use their characters in your ebook. Alternatively, you could create your own original characters or use characters that are in the public domain or licensed under a Creative Commons license.

As always, you should consult with a legal professional to get a more accurate assessment of your specific situation and any potential legal risks.

Public domain characters are those whose copyright has expired or never existed, making them free for anyone to use without obtaining permission from a copyright holder. Some famous public domain characters include:

1. Sherlock Holmes (by Sir Arthur Conan Doyle)
2. Dracula (by Bram Stoker)
3. Frankenstein's monster (by Mary Shelley)
4. Robin Hood (a legendary character from English folklore)
5. King Arthur and the Knights of the Round Table (from various medieval texts)
6. Characters from Greek mythology (Zeus, Hercules, etc.)

Creative Commons licenses, on the other hand, are typically applied to more recent works by their creators, allowing others to use, share, and sometimes modify the works under certain conditions. Creative Commons characters are less common than those in the public domain, and finding them may require some research. You can start by searching for works under a Creative Commons license on platforms like Wikimedia Commons, Flickr, or other repositories of Creative Commons-licensed content.

Keep in mind that the availability of characters under Creative Commons licenses may be limited, and the specific terms of each license may vary. It's essential to understand the terms and conditions of the license before using any characters or content licensed under Creative Commons.

To ensure that you can legally use a character, whether it is in the public domain or licensed under Creative Commons, it's crucial to do thorough research and, if necessary, consult a legal professional.