Bugfatty300
Buddha Squirrel
Uhh.. They're machines designed to kill.
Which can be useful. Hence why someone might own a gun for self-defense and not say a plush toy.
Of course you need a good reason, if you're going to allow people to own them.
If you're going to allow people to have them then why does one have to give a reason? Do you seriously believe they will write down "mass murder" or "bank robbery" as a answer on a prerequisite questionnaire?