Many people don't go to theaters anymore; Cabin has only been out on disc/streaming for a month or two. Perhaps adding spoiler tags for Soylent Green or Sixth

Many people don't go to theaters anymore; Cabin has only been out on disc/streaming for a month or two. Perhaps adding spoiler tags for Soylent Green or Sixth Sense would be a little silly, but in general, it's common courtesy to alert the reader in case they care (and it's not like it costs you anything).