CiviCRM: Unauthorized users are subscribed to mailing list after sending message to CivCIRM Group

Subscribers that are not associated with the CiviCRM Group you subscribe to a mailing list are subscribed and sent messages after sending
a message from the mailing list

Initial Conditions
1. Massmailer module must be enabled in http://civicrm.civicspacelabs.com/home/admin/modules
2. Static or dynamic groups must be created with CiviCRM: http://civicrm.civicspacelabs.com/home/civicrm/group?reset=1

Steps
1. Configure Mailing List Settings: http://civicrm.civicspacelabs.com/home/admin/settings/massmailer
2. Enter an e-mail address for E-mail report address where you can track message confirmation.
3. Save Configuration.
4. Create a Mailing List: http://civicrm.civicspacelabs.com/home/admin/massmailer
5. Manage the Mailing List: http://civicrm.civicspacelabs.com/home/admin/massmailer/list/manage/#
6. Select a CiviCRM Group to subscribe.
7. Add Subscribers.
8. View the members in the Group.
9. Verify one of the user accounts and that you can confirm if a mailing list message is received.
(If you cannot, select a different group with a user whose account you can confirm, or add yourself as a user to that group)
10.Create new message: http://civicrm.civicspacelabs.com/home/admin/massmailer/message
11.Under List Assignments, select the mailing list created in Step #4.
12.Queue Message.
13.Send Message: http://civicrm.civicspacelabs.com/home/admin/massmailer/queue
14.Open the e-mail account specified for E-mail report address in Step #2.
15.Review the PHPlist Maillist Processing info e-mail.
16.Notice that there is one or more e-mails sent and more than likey an e-mail sent to an invalid account.
17.Open the e-mail account of one of the users in the CiviCRM Group subscribed to the mailing list. (See Step #9)
18.Check the inbox and note that no e-mail from the mailing list has been received. (This is related to defect: Users in Groups are not
really subscribed to Mailing Lists when subscribing them from Massmailer Manage List)
19.Manage the Mailing List again: http://civicrm.civicspacelabs.com/home/admin/massmailer/list/manage/#
20.View the Subscribers.

Results
21.There is a bogus subscriber called 28 or some number like 2x.