There is no law that says walking is illegal. There are laws that prevent loitering which has a side effect of encouraging people to not hang out outside. Particularly if you don’t “belong” in the area. Knowing that you will be harassed by police even if you are doing nothing other than walking with too many friends is a form of de facto criminalization. What is being talked about is the effect of living in a culture that does not value or understand a need for walking and the attitude of police forces in this regard. Again, there is no law that says walking is illegal.

As lawyers sometimes say, you can win the case in court but will you survive the time spent in jail waiting for the trial? Effective criminalization is not limited to just what is written in the law.