Is Permission Needed to List Websites in Book?

Do I need to get permission to list websites in a published book? All the websites I wish to include are accessible through Google. Do I need to deal with each site for permission or do I need to deal with Google? You don't need to deal with either; no permission is required when providing the name or publicly-accessible URL (web address) for any website. You may only run into problems listing websites if you are encouraging illegal activity by knowingly listing or linking to sites that promote bad stuff -- for example, child porn sites, sources of illegal downloads, or sites that are exposing confidential information or invading privacy.