They aren't for home use in general- they are for playing airsoft with.
Airsoft can be CQB- in old buildings, or sports halls with barricades etc in, or woodland- which is in forests or fields etc.
It's allowed to shoot in your garden, in most areas (check your city laws if you live in a city though), so long as you don't shoot on to other people's property's- shooting cans in your back yard is perfectly allowed, no one would call the cops for a toy gun!
I'v shot an air rifle allot in my back yard, and in my country people are REALLY anti gun- they go mental about anything!
Don't shoot indoors- you will break things, a bb can go through several layers of cardboard- damage furniture and cushions or sofas etc... it's just a bad idea, you also run the risk of a ricocheting bb hitting someone, it WILL happen, allot, and it's not pleasant- if I shoot the floor, it will bounce between the floor and ceiling a couple of times, and my gun was only 330fps!
If you want to enjoy airsoft, look for an airsoft site nearby, and join there- it's allot of fun, similar to paintball.