A user is destroying precise landuse mapping in Wallis. "Simplifying" in this case turns precise landuse cover into weird angles and destroys the work done by the previous contributors while harming the OSM database. Such moves could furthermore clearly be perceived as aggressive.
 Typical examples of the vandalism can be observed there https://www.openstreetmap.org/way/965324922/history#map=19/46.02973/7.11287

What is the appropriate way to react to such attacks against the project?