It gets tricky when you get into this territory, so make sure you know the laws better than from internet advise or you can end up in jail.
That is the key concept here. No legal system in the country will take "I didn't know it was illegal" as an acceptable excuse. It is the responsibility of each individual to know the laws and how they are applied and enforced.
Some people are like Slinkies - not really good for anything, but you still can't help but smile when you see one tumble down the stairs.
A gun should be a tool in the hands of a deadly weapon, not a deadly weapon in the hands of a tool.