This site did not show evidence of storing passwords in plaintext.
This site does allow secured connections (https)
This site did show a clear way to unsubscribe from their emails
This site does verify your email address.
Below is a sample of the emails you can expect to receive when signed up to CHIPOLO.
Thank you for joining and giving us a chance to help you look for your belongings.
Chipolo started because one of our friends could never find his keys. From there it grew into a worldwide community that helps each other find lost things. In our core, we just want to make things better so thank you for registering, you just made our community a little stronger.
Sincerely, The Chipolo Team
Please do not reply to this email. If you have any questions please visit our support pages.