I recall getting a letter from megaupload a couple of years ago after I downloaded Firefox through their services "for free", asking me to pay some bullshit amount of money. Somehow they got their download link on top of all the others in Google. Did not pay because it was clearly a fraud. Many paid though. Later they busted the operation. In Germany that was.
That's my share on Kim Dotcom.
Filesharing is fine but the dude is a criminal trying to rationalize his deeds to evade punishment.
Years ago Firefox used to have a disclaimer of "Only use this software from official sources, you should never pay money for this software" kind of thing, because that practice happened all the time. Companies made money reselling Firefox to people who didn't know any better or weren't paying attention.
No idea if Megaupload was responsible or not, but it was certainly a popular fraud.