There is an article in October's PCpro page 33 entitled
"Linux patents could cost end users"
about insurance companies selling policies to cover businesses against the financial risk of having to defend a patent lawsuit.
"....claimed Linux potentially infringes 283 patents......."
."...the good news for users is that a third of the 283 patents are held by Linux-friendly developers..."
"...the platform is developing a critical mass to defeat patent claims..."
"..huge Linux user base should give enough mass to confront -and dispatch- any opportunist claims.."