Well they didn't cut off Beeper in the way that would block access to older Apple devices. It seems likely that they found a pattern of access performed (or loo

Well they didn't cut off Beeper in the way that would block access to older Apple devices. It seems likely that they found a pattern of access performed (or looked at the identifying information provided) by Beeper in order to target it specifically from the server side. Those were not protocol changes. The iMessage protocol remains unchanged as far as I know. What I'm referring to above is changing the protocol and updating all clients to use the new protocol so that Beeper is left catching up. This could involve adding new DRM mechanisms or even adding cryptographic remote attestation requirements.