In a recent online conversation (chat) I was involved in, the subject turned to who was actually subject to certain licensing laws. During the conversation, I decided that the facts I was presenting should also be shared on my blog. So, after editing the transcript for spelling and clarity, I offer the following. The question I'm answering could easily be "why aren't I required to license...".
Because of America's system of government. It is founded (as in the foundation of America) upon liberty, and mankind's God-given rights (as in inalienable). What you are referring to as "law" is actually a statute which was passed by a legislature whose powers and authorities only extend to matters "which concern all the members of the republic, but which are not to be attained by the separate provisions of any". They exist for two purposes, to govern the foreign entities who have been granted certain privileges in relation to America, and as a code of conduct for the members of the government itself, which is why it is often referred to as "code" (statutory code, United States code, Internal Revenue code, etc.).
Actual law in America is what a legal court decrees when a statute is tested through trial. It is situation-dependent and relies on the plaintiff's ability to prove the statute is law in each particular case. Because of this, what may be found to be "law" for one person or group of people, may not be so for any other.
The key is Liberty. The right to be free from government interference (look it up). Americans, are guaranteed liberty. Any statute written, which appears to apply to everyone, must be read in light of that fact. So, where the legislature has authority to write statutes, they do not have the right to subject American Citizens to that statute. In other words, they (statutes) only apply to people under the direct authority of the legislature; civilians and foreigners.
No, not all of us are civilians. Remember, America's government is divided into three separate parts, two parts civil (legislature, and judicial), and one part militant (executive). A civilian is a member of the civil government, officers (elected officeholders), delegates, agents, employees, and so on. Most of us (Americans) are citizens.
Furthermore, a statute cannot be enforced. Only law (judgment of the court) can be enforced. Hence the phrase "innocent until proven guilty". And even then, only by a legal law enforcement officer. As the title suggests, enforcement "officers" are duly elected individuals empowered to enforce the law (decree, warrant). Ever seen a traffic ticket? Tickets are not law either, in fact, they are just summonses to appear in court and are themselves governed by statute.
If you looked at most licensing forms and the statutes and regulations which constitute them, you will discover that they were intended only for foreigners who wish to practice certain privileges within the States of America, or government agencies that the government has decided should provide certain services (county hospital, city fire department, etc.). Remember that all statutes are written by a legislature, with limited powers and authorities, under the assumption that those who are within their jurisdiction know they are subject to the statute.
Also, when reading statutes, you have to be able to read EVERYTHING regarding the statute you're interested in. The reason is because legislatures use their own definitions for common terms and words, which is crucial to understand the statute as the legislature intended. Also, you have to cross reference other seemingly unrelated statutes.
For example, most statutes which govern licenses will have some connection to the Social Security Act. Many licenses require social security numbers (SSN), which can only be issued to foreigners and certain benefits receivers. The forms use the term "United States", which is defined in the code (statute) as the District of Columbia, Commonwealth of Puerto Rico, Guam, and American Samoa. Most people, including American Citizens, would have assumed the term "United States" on the form referred to the States of America (the 50 states), and would have no problem signing under the oath of perjury that they were citizens of the "United States", when, in fact, they may never have even visited the "United States" as the term is defined in relation to that form.
Actually, statutes aren't complicated. They are well organized and straightforward and easy to understand. Definitions like the one cited above are often found in their own section labeled "definitions" for each section, subsection, or title they apply to.
It may seem far-fetched, but you don't have to take my word for it. The truth is indeed out there, and easier to find than one would first assume. If you stick to the statutes, their regulations, and the constitutions (state and federal) you'll figure it out in pretty short order. It may even appear mind-boggling that more people don't already know.