Here's one link: http://arstechnica.com/tech-policy/2014/02/apple-top-target-of-patent-trolls-faced-92-lawsuits-in-three-years/ http://arstechnica.com/tech-pol

Here's one link: http://arstechnica.com/tech-policy/2014/02/apple-top-target-of-patent-trolls-faced-92-lawsuits-in-three-years/ http://arstechnica.com/tech-policy/2014/02/apple-top-target-... Mentions Google, Apple and Samsung (respectively 192, 191, 151 lawsuits over last 5 years). Microsoft has mentioned similar numbers, but I can't find a reference off hand. Google for "patent trolls target Microsoft"