This compound noun hitches together
Volk (people--as in "the American people") and
Verhetzung (stirring up of hatred, especially against other peoples or minorities; vicious demagoguery).
Volksverhetzung is a crime in present-day Germany, no doubt in response to the Nazi rhetoric of the past, in which
Volksverhetzung played a major part.
The law is being enforced; i.e. people have been convicted based on it. I remember a case of the recent past, when a Neo-Nazi was convicted under the law for anti-semitic remarks that were considered sufficiently close to Nazi rhetoric. However, I do not know how systematic the prosecution of this type of speech is. More in my first comment...
Note on pronunciation: Both v's are pronounced like English "f". (Remember: A Volkswagen is a Folksvagen in German!).