[SebP]

Right, Dialzoo does not share email addresses publicly.

But it's to the users of the service to share their dialzoo url including their email. Like http://dialzoo/[e-mail]

Our assumption is that people would use email that are consider public info already, and share that.

Perhaps this is more relevant for public profiles such as - business website - public social profiles like linkedin. - facebook - google +

[p4bl0]

Is the point of the service to allow anyone to send voicemail to any email address? Or is it for people who own the email address to allow anyone to voicemail them?

Because in the latter case (which is what I think the service is), you could make the users register their email address (using a verification email to ensure they do not register someone else email without their consent) in your service and then have a map from a random hash to the email, allowing you to provide urls looking like dialzoo.com/nzef1824Ldaw68873 rather than forcing user to publish their email in clear. Or even require a username and use that for the URL.

[toomuchtodo]

Couldn't you do a hash of the email?

http://dialzoo.com/67135a14d3ac4f1369633dd006d6efec

[ryan-c]

The search space of email is small enough that hashing is not a good solution.

http://www.developer.it/post/gravatars-why-publishing-your-e... http://archive.hack.lu/2013/dbongard_hacklu_2013.pdf

[richardwhiuk]

They can add a random seed to the hash to increase the search space. In fact it doesn't need to be a hash - they could just store a random string.