If the text of a question has spoiler text near the beginning, this spoiler text might appear on the
/questions page (example question; question search result illustrating the issue). It'd be nice if the site realized it's not cool to spoil people.
This bug report was initially declined but is now resolved.
This has been mostly completed and is now active - now, the question summaries on the Questions pages, as well as the summary tooltip on the Front Page will hide any spoiler text that is in the first 200 characters.
It's only mostly completed as RSS Feeds and search results do not cover up spoiler text.