When someone cuts you in the line. you accidentally see it and can’t do anything or just let it go. many line cutters also do it habitually and repeatedly. Besides bad manners everyone should know “first come first served.” thus you should do in a better way. For example, If you’re in line of Starbuck in order to buy a cup of coffee with 50% discount Unfortunately someone tries to get in line you just say “ Excuse me ! you need to go to the end of the line.” In this situation line cutter probably hate you but it’s so fair for people who follow the rules.