Heh, I've had experience with commercial film companies and fansubs.
A few years back, I had too much time on my hands, and an itch to watch certain foreign movies that (then) had no publicly available English translation. Not to be outdone just because I was monolingual, I downloaded the films themselves from the internet, downloaded subtitles for *other* languages (French, Spanish and Portuguese) and proceeeded to convert the subtitles into English, using a mixture of google translate, perl, online dictionaries, hand-editing and mass rewatching of parts of the film, until I got something that looked roughly right to me, at the time. It took a pile of time, but as I say, I had too much time on my hands.
When I was done I finally got to watch the film, then uploaded the files to some subtitle database on the internet in case others found it helpful, which apparently a few people did. No matter that what I did had a lot of wrong bits (the hardest part is catching local idioms, which aren't well-documented, even on a place as comprehensive as the internet).
Fast forward a few years, and I spot DVD versions of one of these films on Amazon complete with English subtitles and buy it instantly. Finally, I'll get to see the film with properly translated subtitles, rather than some botch job by someone who didn't know what they were doing. And, of course, it turned out that the Korean company that packaged the DVD had just downloaded my subtitles from the internet, made some small alterations and slapped them on the DVD itself (sadly, not correcting the most obvious mistakes I'd made).
Seems some of these film companies will happily take free fan labour (however shoddy!) and sell it on to paying customers without acknowledgement or royalty*, while others will send in jackbooted thugs to have you sent to jail. Such is life.
*I'm not miffed about my work being used like this - I'm just embarrassed at the terrible job I did and hope the customers aren't upset by it!