A keycap keychain (Song Seung-hyun/The Korea Herald) What began as a popular stress-relief accessory is quickly becoming a source of frustration in subways, offices and other shared spaces.As keycap keychains gain popularity among younger people, complaints about their constant clicking and clacking are also growing.Keycap keychains are small keyboard-inspired gadgets that click when pressed. They come in various designs and provide tactile feedback and audible clicks, making them popular as stress-relief and fidget items.However, many people say the repetitive sounds can become disruptive in quiet public spaces.A commuter shared their experience with a local news outlet on Tuesday after seeing a woman repeatedly press a keycap keychain on the subway."When I gestured for her to stop, she and her companion responded by saying, 'Who are you to tell us not to press it?' and began insulting me," the commuter said.The story prompted others to share similar complaints online."I don't understand why people keep clicking those things in the office," one commenter wrote.Another said, "Whenever I hear that rattling noise on the subway and look around, it's always someone with a keycap keychain. They sit there wearing earphones and clicking away. That's something you should do at home when you're by yourself."The growing frustration has even been reflected in popular culture.A recent sketch on the comedy show SNL Korea featured an employee repeatedly clicking a keycap keychain to calm themselves while being reprimanded by their boss.