Florian Mueller:

It appears that Motorola Mobility, which is in the process of being acquired by Google, has sent Apple an enforcement letter demanding compliance with a permanent (but appealable) patent injunction that was handed down three weeks ago by the Mannheim Regional Court. The Motorola patent at issue in that litigation harks back to the time of pagers, a predecessor of text messages.

Pagers is probably the last innovative thing Motorola did.