Is there / was there any graffiti on the great wall of china?
Considering they can throw you in jail, and throw away the key - no. I don’t recall any and I walked about 10KM, including some less travelled areas (if there are any). In fact the problem is the opposite. Tiles with writing on them or other reliefs, dating from the 1400’s, are going missing. Besides, it’s not like spray paint is a typical item in China, even for in-city decoration… or that someone would go 60km from the city to the nearest wall section with it to commit a desecration.
The signs even remind you to take care not to hurt the historical site.
Well, there is that bit of ancient Mongolian script that says “Zhu Qizhen sucks my wontons”.
This may or may not be what the OP is interested in, but it is more what I’d like to know about. Roman ruins are famous for ancient graffiti, and I’d wonder what the ancient Chinese felt was needed to be recorded.
The Great Wall has a massive graffiti problem. But the problem isn’t spray paint, it’s people scratching into the stone.
It’s more or less impossible to find a close-up picture of the wall which doesn’t have graffiti visible.