zlacker

They could certainly do that in this case, but they are probably trying to send a strong message to would-be developers of similar extensions. One is a nuissance; a thousand would be much more difficult to chase down and block.

Also, if these developers really wanted to, they could distribute it directly from their site and dynamically generate the extension, packaged with a unique identifier, for each download. This would make it effectively unblockable. So simply identifying an install of this specific extension is not a solution.