Are there any well-known cases of open source piracy?
By that I mean cases where a developer releases their project with an open source license and someone else takes their product and markets it successfully, to the detriment of the original developer. It seems like raiding GitHub for code and pumping out cheap software is a possible business model; I'm wondering if there are well known cases of people doing that.
Note after answer 1
An example of the kind of scenario I'm thinking of: Company A develops their amazing open-source software (for example, WordPress) and publishes code on GitHub during development. During the alpha release of the software company B takes the code, makes a couple superficial changes, re-brands it, and then commercializes the software. Company A then has to compete with company B, and this seriously affects their bottom line.
Are there any known examples of this happening?