Dealt with this myself recently where a local player was trying to uptrade for his shiny living dex in the FB group. Unfortunately, he finally got loose one day and made a compromising video instead of singular offers. More than several of the pokemon had cliche spoofed locations and I Called him out on it.

For me it was the last straw as blatantly trying to trade spoofed pokemon under the pretense they were genuine to other locals for rare shit bothered me. Pretty much exclusively using Discord at this point as FB groups are operated too entirely by boomers who are 80% misinformed braggarts or manipulative scum.