You can't tell when something is stolen. I uploaded a family that I created from scratch and somewhere along the line they got tagged as being created by someone else-that sort of infuriated me but whatever it's just a game. All the time people download houses-if they completely make over the lot and rebuild from scratch it's still tagged with the original house they downloaded.
The system is totally flawed.
But I honestly don't care if someone takes my stuff and claims it-I guess I'm just past that sage in life. Getting old? Maybe. I know what I created so meh..
