I was recently setting up an AWS Cloudwatch alarm, that emails me using AWS SNS.

For some reason when I clicked the subscribe link, I would get an “AWS Notification - Unsubscribe Confirmation” email seconds later.

It turns out Chrome pre-fetches the unsubscribe link on the page

You have chosen to subscribe to the topic:
arn:aws:sns:ap-southeast-2:12345678910:alarm-topic

To confirm this subscription, click or visit the link below (If this was in error no action is necessary):
Confirm subscription

Please do not reply directly to this email. If you wish to remove yourself from receiving all future SNS subscription confirmation requests please send an email to sns-opt-out

Your subscription to the topic below has been deactivated:
arn:aws:sns:ap-southeast-2:12345678910:alarm-topic

If this was in error or you wish to resubscribe, click or visit the link below:
Resubscribe

Please do not reply directly to this email. If you have any questions or comments regarding this email, please visit AWS Support.