>>1697294They kinda should be replaced periodically as they naturally get bashed around and won't work so well so I just clip it through a wheel/ the frame or over the stem/bars and if someone steals it, so be it, good excuse to get a new one that will protect better.
But it's been years and no one has ever stolen a helmet from me.
If you're a noob who parks his bike badly so it falls over then don't do that because you could damage it.