There is a fashion to print all kinds of nonsense on T-shirts, and not surprisingly, it becomes ugly sometimes.
At best, it ends up with tourist in China buying a T-shirt with pretty hieroglyphs saying "I'm a stupid foreigner, who can't read Chinese".
At worst, a British company selling the following shirts with the following message:
For the non-Russian speaking folks, the writing around the Russian coat of arms says:
"We will clean Russia from all non-Russians".
Definitely not funny.