The thing is, Laws do not forsee in all cases, and language is not completely objective, so you cannot avoid judgement calls. One example is computer hacking, which in many jurisdictions is specified in very vague terms.

Another example is that in the Netherlands, there's a crime called "valsheid in geschriften" which exists to make it easy to prosecute fraud. It states that if you create a document with false information with the intent to use that document to deceive, you can get up to 5 years of jail time or some really big fine. Is lying on a paper insurance form to get a cheaper premium breaking this law? This doesn't seem clear cut to me.