Don't wear Hawaiian shirts.
I just got an email from my aunt, whose husband is a cop. It said that there's a gang that wears Hawaiian shirts, and they've been killing unsuspecting victims who don't realize that Hawaiian shirts are part of their gang clothing. One guy was able to get away, but he said they came up to him and asked him to flash the Hawaiian shirt gang sign, and he didn't know how, so they loaded him into a car and took him out to the docks. They took his shirt, sealed him in a crate and dropped it off of a pier, but luckily he was able to kick his way out and swim to safety, because he used to be a commando.