They are available to licensing. Motorola offered to license them to Apple under FRAND terms and Apple refused (said the terms weren't good enough) and used them without a license.

This is not the first time Apple has been sued for this - it seems to be a common occurrence for them. People offer them licenses for the FRAND patents they're using under FRAND terms, Apple denies them, and then when they get sued they say "But these licenses are FRAND! This doesn't make sense!"