Not to get too pedantic, but you might want to amend that to "9mm handgun" or something similar. Apache helicopter gunships shoot 30mm projectiles!
But to address your argument - a large portion of the gun lobby and gun enthusiasts aren't necessarily uncomfortable with just a handgun for defense, but they are uncomfortable with a technically ignorant government deciding what is sufficient and allowable for that purpose. Similarly, what's to say a precedent established with Megaupload cannot be used to hamstring or shut down Dropbox or similar services? Though you can understand and make the distinction between the intents of the two services, can you trust a judge to properly frame why Megaupload is bad and Dropbox is good? Or for prosecutors, lawyers, and the assembled IP industry to not leverage any legal precedent to shut down what they feel like?
But to address your argument - a large portion of the gun lobby and gun enthusiasts aren't necessarily uncomfortable with just a handgun for defense, but they are uncomfortable with a technically ignorant government deciding what is sufficient and allowable for that purpose. Similarly, what's to say a precedent established with Megaupload cannot be used to hamstring or shut down Dropbox or similar services? Though you can understand and make the distinction between the intents of the two services, can you trust a judge to properly frame why Megaupload is bad and Dropbox is good? Or for prosecutors, lawyers, and the assembled IP industry to not leverage any legal precedent to shut down what they feel like?