Conversation so far:
why did the tradition of fancy dress for halloween begin
The practice of Halloween Costumes may have originated in a Celtic festival called Samhain, held on 31 October–1 November, to mark the beginning of winter.
how much money is spent on halloween costumes
In 2017 it was estimated that Americans would spend $9.1 billion on Halloween merchandise with $3.4 billion of that being on spend on Halloween costumes.

Question: has the practice caused any controversy
Self-contained rewrite: has any halloween costumes caused any controversy