[SilverRed]

This analogy still works. The staircase is not public, its in your house. Which would map to running on your local computer or local network.

As soon as you turn your house in to a public venue (put your code in use for the public) you now have to worry about accessibility and safety. If that stair case collapses because of your dodgy building, you are liable. But you are free to fall off your own staircase in your own house.

So people are free to run whatever they want on their computer. But once you start taking user data, you now have legal responsibility. User data is hazardous waste that needs ultimate care.