Garrett: The ongoing fight against GPL enforcement

They don't. It's all of a big 'IP rights' soup for them (the latest Oracle vs Google complaint is a good example; we make the distinction because we want to be clean and tidy, proprietary houses stuff all in the same bag).

For the practical use case presented here (assemble bits sourced elsewhere in an hardware appliance, without checking legalities) there is *no* distinction between patents (for hardware components) and free software licenses (for software). They behave the same way. If you put unclean parts in your products you can be sued directly.