Kyle Gilman

This plugin does one thing and one thing only. It adds the text <code><meta name="robots" content="noindex"></code> to the header of any password-protected post. Google and all other respectable search engines will leave your password-protected pages out of their search results.

Noindex Password-Protected Posts

Disables search-engine indexing for all password-protected posts.

room34

This plugin is an add-on for Modern Tribe’s The Events Calendar plugin. It adds a “noindex” meta tag to the individual detail pages for events after their end date has passed, to prevent them from appearing in search engines like Google or Bing.
Note that this only takes effect the next time a search engine indexes your site, so past events may still appear in search results for a few days.

noindex Past Events for The Events Calendar

Automatically add a "noindex" meta tag to The Events Calendar's detail pages for past events, to prevent them from appearing in search engines.

Noindex Password-Protected Posts vs noindex Past Events for The Events Calendar