How old okay to trick or treat alone?

I was surprised this evening when parents of a group of 6th graders insisted on accompanying them trick or treating, on a quiet neighborhood street with no traffic (roads closed), and a big street party (lots of people around). Is 6th grade not old enough to trick or treat alone? Pretty sure I went out with friends in 4th grade, definitely 5th. Have standards changed? When did you let your child trick or treat solo? via /r/Parenting https://ift.tt/2Y4feMD