These addresses can be used for other, much more terrible things. I do not think it is right to sell them, first you have no consent of the owners to do, and second, create a dangerous precedent.
Anything can be used for "much more terrible things," including crypto currencies as a whole may I add, but each is responsible for their own actions. I have consent of everyone who signed up to my mailing list as it was done through Mailchimp ( user had to sign up + verify email + agree that they were agreeing to opt in). This is completely fine as long as the option to opt out is included by whoever may purchase this in the future.
you have "consent" thru fine print noone reads :/
if any of those users were asked right now if they consented to their personal data being sold to the highest bidder i assure you they would most likely say "fuck no"
screw you man, i have left a neg to the kind of person you are. (keep in mind trust ratings are unmoderated and user-generated)