Are email addresses of Launchpad users visible to other users? What about to Google?

By default, email addresses of validated Launchpad users are visible to all other logged-in users of Launchpad. This means that, by default, if I am logged in to Launchpad I can visit your personal page and see your email address. This applies only to validated users: it is not possible to view email addresses for inactive people in Launchpad.

No email addresses are ever made visible to Google (or any other bot or user which is not logged in to a Launchpad account). The rendering code for emails checks to see if the user viewing the page is logged in; if he is not, then the email is replaced by a link to the user's Launchpad page. To see this for yourself, try visiting a user page while logged out -- you'll find no email address is rendered.

Finally, there is an option available to all Launchpad accounts that allows hiding email addresses from logged in users. The option is available at https://launchpad.net/people/+me/+edit and is labeled as "Hide my email addresses from other Launchpad users". If this option is active then email addresses are not disclosed through the web pages to other users, even if they are authenticated.