I thought patent trolls set up a shell company for each litigation effort, then "license" the patents to the shell, and proceed to litigate from within the shel

I thought patent trolls set up a shell company for each litigation effort, then "license" the patents to the shell, and proceed to litigate from within the shell, with the intent that if it turns out badly for them, they fold the asset-less shell, and collection is thus impossible. Is anyone familiar with patent trolls' business model, and can comment on the feasibility of actually collecting a judgement like this?