According to a report from Cloudmark, at least 30% of all mobile messaging spam is coming from iMessage accounts. Cloudmark’s research report was led by security expert Tom Landesman.
Landesman says that iMessage makes it possible to target people on multiple platforms, so that could be part of the reason why spammers are using the service. An iMessage account is able to reach iPhone, iPad, and Mac devices, allowing the reach of spam to be much further than if the spammers were using alternative systems.
There are also a slew of features in iMessage that make the service great for regular users, but also great for spammers. For instance, read receipts allow the spammers to find out which numbers are best to target; if a person has read the message, it means that the number is completely active.
Spam reporting is possible inside of iMessage, with Apple hoping people can report messages and get iMessage accounts banned when necessary. Since that option has been included for a while, it doesn’t appear to be having a huge effect on the overall iMessage spam problem.