UPDATE
Amazon has added the ability to block contacts. In the Alexa app, open Conversations (the middle tab) > tap on the contact list icon on the top right > scroll all the way down to Block Contacts.
Earlier this week, Amazon launched its own Internet voice and messaging service, Alexa Calling and Messaging, available free to all users with an Amazon Echo, Echo Dot, or Alexa app for iOS and Android. You can also use the service on Amazon’s new device, Echo Show, a touchscreen with a 5-megapixel camera and the company’s voice-enabled digital assistant Alexa built-in. But some users have noticed they don't have the ability to block people from calling their Echo devices — and find it unsettling.
Before you enable Amazon Alexa calling know that it imports EVERY phone contact and you can't delete or block them. https://t.co/6CVSbF2bM1
To use Alexa calling and messaging, users need to verify their phone number and import their entire address book, which a spokesperson says is stored "securely in the Amazon cloud." Your phone number essentially becomes your username and, like on WhatsApp and Signal, anyone with your phone number will be able to contact you on your at-home Echo or Echo Dot (including, er, PR people, much to the chagrin of this reporter). The key difference is that WhatsApp and Signal allow users to block certain contacts, while Alexa does not. You can, however, turn on Do Not Disturb for Alexa, by telling your Echo, "Don't disturb me." But that only ignores calls instead of blocking them, and only when Do Not Disturb is turned on.
I'd feel a lot better about @Amazon Echo's new calling features if Alexa didn't need access to my entire contact list. Not falling for that!
There are other privacy concerns as well. There's no password protection to use Alexa calling, which means anyone in your household can make an Alexa call using your account. They can also ask your Echo device, "Play my message" when you receive a new text or voice message (Alexa calling does not support voicemail) and listen to that message without your consent.
If learning all of this means you're reconsidering your decision to enable Alexa Calling and Messaging on your device and you want to turn it off, it's a lot less straightforward than you might think. I combed through Amazon's entire Alexa-to-Alexa calling support site to find out how to deactivate calling and messaging but couldn't find instructions, so I reached out to Amazon.
As it turns out, users will need to call Amazon customer service to disable the new feature. You can do this one of two ways:
1. Call the general help number toll-free at 1-877-375-9365.
2. Go to this special Contact Us page and select Amazon Devices > your Echo name > Echo Devices > under "Select issue details," Something Else > under "How Would You Like To Contact Us," select Phone. You will then enter your phone number and an Amazon rep will call you.
I tried the second method, and it took 10 minutes for a representative to deactivate calling for my Amazon account.
If you don't want to disable the feature but you want more privacy, try using a burner number.
If you still want to use Alexa calling and messaging with a limited group of people (like the grandparents), sign up for a Google Voice or Sideline number (both are free), then use that number when setting up Alexa calling. Then, have your friends and family add that number to their address book and use it when they want to talk to you on your Amazon device.