A boy called Finn got dared by his friends to film himself doing something risky and post it — the kind of "challenge" that goes round online. The dare came with the usual push: everyone's done it, it'll get loads of views, don't be the one who's too scared. Finn did it. The video got attention, which felt great for about a day. Then it spread further than he meant it to. People he didn't know were commenting, some of them nasty. A teacher saw it. His parents found out. The thing that was supposed to make him look brave for a moment is now something he can't take back, because online, you can delete a post but you can't really un-send it.