Microsoft might not be the specific problem here but they're still a big problem. Reason being
that if Microsoft start attacking Linux with patent suits for their so far fantasy claims of
235 (or so) infringements it is likely to cause a major retaliatory set of suits from people
like IBM. The obvious way for them therefore to use patents to attack is through isolated
mediums like intellectual property companies that make no products and therefore are pretty
much immune to being sues back.
Such companies are inevitably going to be the assassins of choice for a company like
Microsoft. They have a record of it.