A new knowledge base article on Apple’s website introduces an iMessage spam reporting system.
To report unwanted iMessage messages to Apple, please send an email with the following details to: email@example.com
- Include a screenshot of the message you have received.
- Include the full email address or phone number you received the unwanted message from.
- Include the date and time that you received the message.
While iOS 7 allows for blocking Apple IDs for iMessage or FaceTime, this feature will allow users of iOS 5 and up to report unwanted iMessage messages and allow Apple to investigate the associated account..
(via Beau Giles)