You are allowed to own one as long as it is kept inside your own home. At the point where you take it into a public place (where the public have access to by payment or otherwise) you commit an offence and can face conviction.
Also, inside your own home you are allowed to use reasonable and necessary force in protecting yourself or others. This does not include asping someone in the head unless they were armed.
Also, inside your own home you are allowed to use reasonable and necessary force in protecting yourself or others. This does not include asping someone in the head unless they were armed.