I think what he meant was that you can't be punished for being an "illegal alien" in the Netherlands.
"Illegal residence is only punishable if the party involved has been declared 'undesirable'" (http://en.justitiaetpax.nl/project/aliens-detention-in-the-n...)
wsc981 made an unfortunate language error / directly translated a Dutch expression to english; 'being illegal' in his example translates to living in the Netherlands as an illegal immigrant, which, while 'illegal', is not actually enforced as a crime.
Not be picky or anything. What precisely is the language error? I read the sentence and understood the meaning conveyed.
How does one "be illegal"? I think it doesn't make sense (or is at least ambiguous and confusing) unless you replace it with "being here illegally".
He means 'being illegaly there', i.e. being an illegal immigrant. This was part of a recent political debate; it was reconfirmed as not being punishable.
It would have affected mostly individuals that are also banned from entering their homeland, and are ping-ponged back to the Netherlands.
This doesn't make sense as a sentence. Surely the Netherlands has a justice system and prisons, and surely those people in prison are there because they were convicted of doing something illegal. So it stands that you can and will be punished in the Netherlands for doing something illegal.