Since WooCommerce 2.2 password protected products are not hidden by default anymore because we believe catalog visibility should be set via the ‘Catalog visibility’ option.
The ‘Catalog visibility’ option can be set in the ‘Publish’ meta box.
Because there might have been shops that are relying on password protected to be hidden, and don’t want to manually change the ‘Catalog visibility’ for each product, I’ve written a small plugin that will hide all password protected products again.
It do not work on category pages, Working on sidebar featured listing