Microsoft has been making those claims for a while now, and have not actually been able to point to a single patent they claim linux infringes on - they claim they haven't finished figuring out which patents they just know it violates 295 (correct figure) of them... it's like me saying I know someone broke the law, i just don't know what they did... in which case i wouldn't be claiming to know they did something illegal if i didn't know it!
it's purely a M$ bullshit campaign in an attempt to extort cash from commercial linux vendors, several have already decided to pay up without even asking for evidence... and those are the only ones who will ever pay anything, making those companies less successful due to lowered profits from their decision to donate some of their profit to microsoft