There are certain costumes we just don't want to see around Halloween.
First and foremost, anything racist or misogynist. How many times have I seen people attend a party and look at the event as an excuse to exercise bad taste? It's one thing when some idiot attends a private party, but sometimes they actually set example for children. This has gotten worse in the last few years as adult costumes have become more and more inappropriate. Now, I'm not one to shy away from bad taste, but I do tend to hold up my nose at boorishly bad or unimaginative. I was going to post a photo of a toddler wearing a costume with a bloody alien erupting from its chest, but even I couldn't go there.