Josh Rosenthall published an informative article on Edible Apple about Samsung using RAND (reasonable and non-discriminatory) patents against Apple. From the article:

Whereas the patents asserted by Apple against Samsung are completely owned by Apple and unencumbered by any outside obligations and restrictions, many of the patents asserted by Samsung involve technologies that are part of established technological standards.

Because Samsung’s patents are part of an industry standard, it must be licensed equally to parties implementing the standard without discrimination. If Apple implemented an industry standard without licensing the applicable patents from Samsung, it makes sense for Samsung to pursue a license deal from them. But using these patents to defend against Apple’s existing lawsuits is like fighting a forest fire with a water pistol; just plain confusing.