Try to consider this. Suppose you're attending a class of a "killer" professor. Most of the time, he only mumblings aimlessly. Then, on the final examination day, you suddenly realize that the questions presented do not contain a single thing that has been taught in the class. It's completely different and you stare blankly at the exam paper. What do you feel? That it isn't fair? That it seems like the professor is cheating the student? Well if you think so, I would completely agree. This is not fair at all. In fact, if I were you, I will definitely report the professor to the higher ups and ask him to be removed since this is so unprofessional.
But if you think it through, wouldn't you find the similarities between the case above and the legal principle that we are now discussing? With so many regulations issued each year, in reality we've already drowned in regulations (and the parliament is still thinking about issuing new regulations each year?). No human being, even the best lawyer in the world, can know and fully understand the entire law in a single country. And yet, with all of these facts, there would be no excuses for all citizens to say that since they don't know the law, they should be exempted from legal liabilities in case they mistakenly violate a law. How can that even be possible?
Apparently, there is a good economic reasoning for this certain principle and that is the fact that the cost of faking your ignorance of the law is so cheap (as easy as I say: "I don't know") that opening the possibilities of exempting people out of ignorance would be a major disaster for legal enforcement. Of course, this is not a perfect solution. When the laws aren't as many as nowadays and when the laws are usually still in line with basic common sense, adhering the non ignorance principle would be a good choice. But the case would be different with the current development in legal system.
One of the issues that was discussed today is the fact that there are a lot of new laws in the United States that criminalize acts without any mens rea element. Mens rea basically means the intent to violate the law or the "guilty mind". In other words, you can be criminalized for doing certain acts even when you do not have any intention to conduct such act. Let us take an example, suppose that there is a local law that restricts people to put their cars on the road sideways in certain hours. Say that the regional parliament members have their own reasoning and it is common for the people there to put their car on the road sideways. Wouldn't you be surprised when one day you are being fined for putting your car in the sideways without any warning whatsoever and you can't defense yourself on the basis that you don't know about that law?
What was considered as a good legal principle can be turned into a giant mess. Try the regional regulations in Indonesia. It's very hard to access any information about these laws, there are plenty of them, and each person, including companies, are expected to comply with all of the requirements set out under these regional laws. It does not work that way and a legal system that works like that is no different than legalized burglary.
Having said that, I have to admit that finding the right balance is difficult. On one side, we do not want to provide huge incentives to people to violate the law. On the other hand, we can't let government officials do as they please without proper restriction or we will end up with high cost economy in many part of our lives. Some suggestions would be: (i) with respect to criminalization, the government should be careful in not creating too many new criminal acts, it sends the wrong signal and it increases inefficiency in state management; (ii) even if we need to criminalize, adding the element of mens rea would be helpful in reducing unnecessary violation; and (iii) socialization of new laws is imperative and it would be better if the Government can introduce those kind of laws gradually. Remember the introduction of seat belt rule?