"But, but, but … I found it on the Internet!" Many people today think that just because the image or text is found on the Internet that it is free to be used or copied, as if the copied item were in the "public domain."

Of course, copyright law (and licensing) is determined by the laws of particular countries. What is law in one country may not apply in another country, but in many cases copyright laws are shared between countries via international agreements. As a rule of thumb, I tend to adhere to the strictest set of laws to protect myself, and the strictest set of laws tends to be from the United States.

The United States is so focused on copyright (and patent) law that they built the beginnings of these laws into their Constitution – the same document that supposedly guarantees the freedoms of US citizens also guarantees the existence of copyrights and patents and sets up a copyright and patent office much sooner in the document than the part guaranteeing freedom of speech.

What is not stated in these few words of the United States Constitution are all the terms, conditions, and rules of copyright and patent law [1]. These are regulated by many pages of legal words developed by lawmakers over time. Simplified, these laws state: If you write it, paint it, or take it as a picture, and it is your original "work" (or art), you have a copyright on it.

Period. End of discussion.

Your work is then guaranteed protection for a certain period of time, after which it enters the public domain.

The laws then go on to tell you how you can register your work to better protect it and make sure that people know it is yours. If someone else copies it, you can get even more damages from them.

To better inform people that they need to do something in order to use your work, you can include a copyright statement in or somewhere around your work. This copyright statement might say something along the lines of "This work is copyright" and include a date and perhaps a jurisdiction (i.e., "in the United States") to indicate what set of copyright laws you are following and what length of time the copyright will apply before your work does enter public domain.

Public domain is a real, legal phrase that has true legal meaning. Simplified, the meaning of public domain says the work is available for any type of use, and the original author has absolutely no rights at all to say how it is used, changed, or otherwise distributed.

Which brings us to "licensing," which is how you are going to share this with other people.

Normally a license gives certain rights to another individual or company to do certain things with the work in exchange for some type of compensation. This may be a very long legal contract made between the person wishing to use the work and the owner of the copyright. Many times (but not always) the compensation for using the work is money, but it could also be a "trade" of rights or other type of compensation. Nevertheless, there needs to be a license of some type, or else the user is definitely doing copyright or patent infringement whether or not they know it, and whether or not the original creator is aware of their infringement.

An exception to this (mentioned here to eliminate people screaming at me) is a concept known as "fair use," a fairly complex set of circumstances and rules where a person may use some small part, usually to review or make some point other than blatantly use an artist's whole work. Short quotations from a book or speech, usually with the original artist's name is an example of fair use. These rules may change from country to country.

The path to getting a license from the original author may be difficult. Both for the artist and the people who wish to use the art, "permissive" licenses were developed that give people certain rights to the art.

Examples of permissive licenses are open source licenses, some of which have few rules and regulations about how you use the software, or more demanding licenses, such as the GPL, which have very specific requirements about how you use and distribute the code.

More conductive to art and text are Creative Commons licenses, which can be very permissive (making few, if any demands) or more restrictive , requiring attribution or limiting your rights to noncommercial use.

I am at a conference where this topic came up, and people were genuinely convinced that "if it is on the Internet it is in the public domain." No, to be safe, assume that it is not in the public domain, and look to see what rights you have instead of assuming that you have the rights to use it.