As a regular browser of the Firefox Add-ons site, I'm troubled by the apparent proliferation of proprietary extensions in the last year. Maybe I've simply exhausted the free-licensed extensions that interest me, but recently every interesting-looking extension seems to be a proprietary one -- especially in the recommended list. Nothing, of course, in the Mozilla privacy or legal notice prohibits proprietary extensions simply because they are proprietary, but I find them not only contrary to the spirit of free and open source software (FOSS), but, often, annoying attempts to entangle me in some impossible startup.