I'd say instead randomly stop 50% of people coming to the next game dressed as Mexicans (uniform et al) from entering the stadium.

You don't see how that could be just a little bit problematic? Like, maybe, huge lawsuits against FIFA for racial profiling?

And how would you feel if you had paid hundreds of dollars to attend matches at the World Cup, and then you were stopped at the stadium gate because SOMEONE ELSE who *might* be of the same nationality as you was acting like a clown at a previous match?