If we all had lightsabers, crime would be rampant. The thin concrete and wooden walls that keep thieves away from us and our cool things obviously won’t slow down lightsabers very much at all. This will of course be a problem as soon as lightsabers arrive in our world, but once the wave of displaced workers arrives, it will get a lot worse – just hordes upon hordes of unemployed lumberjacks roaming the suburbs, looking for easy money. There honestly wouldn’t be much point in locking your door at night once this happens, so likely is the chance of a burglar-shaped hole appearing in the wall beside it.
This will inevitably lead to a lot of confrontations between lightsaber-armed homeowners and lumberjacks, and some seriously clumsy fucking sword fights. Around this point, the government will consider its dwindling supply of body bags and street sweepers clogged with limbs, and decide it’s seen enough. Martial law will be more or less inevitable, and we can expect to see massive sweeps of the population to collect lightsabers.