i would make it so that every time they try to go to a website it sends them to a different, random website
it would eventually swap out some of their files with random images from those websites, and would later randomly close tabs, pause videos, sign them up for random paid subscriptions, create them accounts for random websites, change volume and brightness, change backgrounds and profile pictures, post ai-generated images on random websites they had an account on, start competitive rounds of online games and randomly play a really loud, annoying, 20 second long noise