A crime is only a crime when it is defined as a crime otherwise there can be no enlightenment, no progress or moving forward on morals. In fact by your definition society can't progress at all because progress is change and change is damage to the existing society. Though it does explain why thinking is a crime.
I find that's extremely odd philosophy and is making huge leaps of logic you aren't really mapping out in any manner here so I'm interested in hearing why you think those things are at all related.
In game terms, a crime is not a crime because it's defined as one. It's just a behavior that negatively impacts society and if its present, it's taking place. There are crimes that we define in legal codes that aren't actually crimes at all except by legal definition. Though, usually, those are still to some extent true crime because they impact, perhaps not the greater good, but the good of a select special interest.
Examples:
Murder: Whether you call murder a crime or not doesn't mean it won't have a negative effect on the people in the community when folks are engaging in it.
Murder creates paralyzing terror within the society, tremendous grief, lost productivity from both the loss of the knowledge and expertise and skills and all the applications thereof that said homicide victim brought to his economy, loss of productivity due to the need to compensate for overwhelmingly crippling emotions of secondary victims, aka, those relating to the victim.
I could probably write a novel sized reference on why murder causes damage to a community, as very little causes worse. Not only that but its tremendously unfair to the murdered, a theft of the hours remaining in their mortal lives.
Whether you call that a bad thing or allow people to do it all they wish will have zero difference in whether it is harmful to society or not! It's GOING to create problems when people do it.
EXCEPT that to label it a crime, and in more advanced legal systems dictate a guideline of punishment for said crime, then you are empowering a justice-based approach to deterring folks from engaging in this behavior.
Thus, the definition of a crime is a tool used to create deterrence to that behavior. THIS is a tool that was eventually learned, advanced and refined over the years that humanity has struggled with the naturally occurring potential for this behavior and many other crimes.
People didn't have to figure out that murder was possible to do - that we've known since the dawn of time and as soon as we understood our own mortality and how our own lives could end. As predatory apes, we knew what killing was by what was required to survive and even then the consideration of what the response would be if we killed another of our own had to be considered. Ape studies show this.
Money Laundering: You aren't going to automatically understand what this is about until you've advanced your society to the point that they are likely to realize they can do it.
That will happen long before we start recognizing the problem and doing something about it. However, while there is a tech to represent when people start figuring out that this can be a useful strategy to employ, a crime to engage in, just because we don't have a tech to represent when the law starts enforcing codes against it doesn't mean that overall lower crime levels won't keep people from doing it.
The overall crime property levels represent the conditioned sense of moral behavior among the population. Just having a sense of values would keep a person from engaging in money laundering even if it isn't a crime, and the enforcement and deterrent of other crimes may have well conditioned the society so that its people generally wouldn't engage in this practice, even once it's possible to figure out how to do it.
That said, in Outbreaks and Afflictions, we'll see the ability is added to start giving points, in techs and policies, where society does determine ways to deter SPECIFIC crimes and have either the assumption or the option to use those tools. This is where we can place recognition in the civilization that a crime should be labeled as such and included in the legal codes.
Until that mod is on and working with crime, we must consider all crimes to be
as quickly recognized and
deterrent attempts made to the best efforts of all branches of law enforcement,
as soon as people figure out they can engage in the crime behavior. THAT is what the crime unlocking tech represents.
Mind you, yes, theft has been around forever, but organized theft as a profession has not, and at the point where the tech is discovered, your people have figured out this is a thing they can actually specialize in doing - and if your crime levels are high enough, that's exactly what they begin to do on a scale that is damaging enough that it registers as an autobuilding in the city where crime levels qualify.
Your example of Internet Crimes, for example, kinda require that an internet exists before people can start engaging in those destructive behaviors. Therefore, the internet crime would have at minimum a tech requirement and should also require the internet infrastructure is established and in place to commit said crimes through.
Also, just because nobody has said you shouldn't do something doesn't mean it isn't already pre-existing negatively impacting behavior and should have been considered a crime all along. It doesn't start harming the community when you realize it. It starts harming the community when it's
happening. If there isn't actual harm to the community, then it isn't actually a legitimate crime according to the game standards.
Thus:
Prostitution: It can be debated whether this should be considered a crime or not.
This is not because you cannot directly point at ways that it harms a community. Clearly, it can. You can also see ways in which it harms the community to call it a crime and make it a punishable offense.
By criminalizing it, you may increase black market prostitution, thus making it very difficult to actually keep from happening and making it all the more an unsafe a practice when does happen because its done in a much less safe manner.
You might be increasing the likelihood of other sexual crimes taking place that would have had a safer outlet by engaging in prostitution if it were made legal.
You might be inviting murderous vigilantism against prostitutes by declaring it criminal.
Obviously, the practice is generally a harmful one, both to the sanctity of the family bond and to the enabling of disease transference, as well as how much it opens up the likelihood of sexual exploitation and sex slavery.
Of course, calling it legal can give greater controls over those things by making the black market, unregistered, unregulated forms of it less profitable to engage in.
Still, it is morally repugnant to many and perhaps it well should be.
So do you call it a crime or not?
Thing is, it's going to happen whether you call it one or not, it's just going to happen to differing degrees and impact.
You can also assume that it will happen overall less if you consider it a crime. In game terms, it will happen at a frequency that becomes more dependant on the crime level in the city.
Thus, not considering it a crime gives you, in the game, happiness-producing, profitable, but disease spreading buildings, but disables the 'crime' autobuilding side of it, whereas if you declare it criminal, the crime opens up and those buildings are disabled, so only bad can come from it, but you can control that bad by controlling your crime levels - the enforcement and natural conditioning to not commit crimes among the public.
As for ZoC, I completely agree with Toffer - the natural structure of the strategic side of the game already lends to this. I would further that by saying I don't see there being a gap in how map strategy works that needs to be resolved by a ZoC mechanism or device at all. The only thing I could maybe see taking place is forts slowing enemy movement adjacent to them to ensure that units can't slip past without potentially being attacked by those inside the fort. BARRING the movement is not an appropriate reflection of that consideration imo. But making movement more costly might make sense.
From a purely mechanical perspective on ZoC, there are few game mechanics that cost more turn time, and no appropriate strategy to speed things up has been found. Even having it, whether on or off as an option, demands an allocation of memory per plot that is rather costly as well.
You may disagree with the inventor as to what it represents, but all I can say is he meant it to be a reflection of what you termed 'fields of fire'. He made that clear to me in PMs.
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