Health insurance form and other information for a child
School report for a child
Mortgage information
Book library late notice
Nail product order confirmation
Multiple confirmations of job applications
PS4 account information
Various invitations to family gatherings
etc.
Whenever I could find the relevant information, I contacted the various people that send me the original email to correct the information. Most did not respond (including the father of a child with the above mentioned information who was copied on one email).
Sometimes the emails contained an unsubscribe button (yay) but, upon trying to use it, it asked for a password (which I obviously did not have). So, off to the spam folder...
So, I completely agree that Amazon's registration process is very flawed ... but there seems to be a lot of clueless people and businesses out there as well.