hmm, zealots eh? kind of pejorative don't you think? i didn't say one has to agree with everything that they say, only to be aware that such a thing even exists.
ever look at the source code? you'll find that GNU GPL license in a whole lot of programs that do extremely useful things. programs with the same functionality as those that cost hundreds, even thousands of dollars.
maybe you don't use open source personally, and that's fine. the FSF does help keep open source open and free. before you knock them take a moment to think about what you're saying. i'd bet you dollars to donuts that if you've visited more than one website or sent more than one email in your life then there is a very good chance a linux server running GNU GPL'd programs was involved. if so, then those zealots helped make your day better, didn't they?