updated 08:11 pm EDT, Wed July 31, 2013
Can affect Messages app thanks to group MMS, SMS use
While under normal circumstances most users would never see an unwanted or "spam" message in the OS X and iOS program Messages, Apple has now set up abuse reporting mechanism to help deal with those who have the issue. Using the email address email@example.com, users can send a screenshot of the unwanted message, phone number or email address of the spammer or harrasser, and time/date info on the message. Unwanted or spam SMS and MMS messages should still be reported to users' cellular providers rather than Apple.
The post shows how to identify if an unwanted message is coming in as an SMS (traditional text) message or an iMessage or FaceTime call. It also instructs users on how to take a screenshot on an iOS device (press and release the sleep/wake and home buttons at the same time) and how to do so in OS X (command-shift-3 for the entire screen, or command-shift-4 to select a specific area). The screenshots are automatically saved to the Camera Roll on iOS devices or the desktop on Macs, and can easily be attached to an email from there.
Apple is looking to take a proactive stance on the possibility of iMessage spam. As mentioned earlier, the company cannot control spam or unwanted SMS messages even though they appear in the Messages app, since they are controlled by the cellular provider and should be reported to the carrier rather than Apple. SMS spam and trickware (messages that entice users to vote or respond without making it clear that they are signing up for a paid subscription) has been a major source of legal issues and problems in the smartphone community, and a virulent source of malware for Android phones.