Because you, as the host, define the availability of the file on the server. If you have chosen not to apply any access control or authentication (the right tools for declaring that access to something is restricted), then it is effectively publicly available.
To then try and use referrer information to restrict access is a poor substitution for access control. Not just a poor substitution, but actually ineffective (all SSL access gets around it, as would all wget and curl requests).
Trying to secure anything with referrer checking is equivalent to having a house and putting a sign on the front door saying it's locked, but leaving the windows wide open and the back door open. It's dumb.
Also... it most certainly isn't theft, or stealing, as the act of theft deprives the owner of something. To request a file from a server and to be granted a copy of that file isn't theft.
It's not even unauthorised access to a computer, as you configured your server in such a way that permitted the access.
If people want to limit the bandwidth used by their hosting of pictures, then they should use the right tools... authentication and authorisation.
Because you, as the host, define the availability of the file on the server. If you have chosen not to apply any access control or authentication (the right tools for declaring that access to something is restricted), then it is effectively publicly available.
To then try and use referrer information to restrict access is a poor substitution for access control. Not just a poor substitution, but actually ineffective (all SSL access gets around it, as would all wget and curl requests).
Trying to secure anything with referrer checking is equivalent to having a house and putting a sign on the front door saying it's locked, but leaving the windows wide open and the back door open. It's dumb.
Also... it most certainly isn't theft, or stealing, as the act of theft deprives the owner of something. To request a file from a server and to be granted a copy of that file isn't theft.
It's not even unauthorised access to a computer, as you configured your server in such a way that permitted the access.
If people want to limit the bandwidth used by their hosting of pictures, then they should use the right tools... authentication and authorisation.