1. A system comprising a storage device including a data store arranged to store a plurality of data records associated with physical hardware modules which can be assembled by a user to form a coherent physical whole object which acts as a user input device for an interactive software experience, each data record relating to a physical hardware module and comprising: an identifier for the module; and at least one field defining a property of the module; wherein at least one field in the data record is verified by an authentication service and wherein the data store is further arranged to communicate with the interactive software experience to cause a change in behavior of the interactive software experience in response to a check of a plurality of data records in the data store; and at least one of: each data record further comprising an identifier for an owner of the module and at least one of the identifier for the module and the identifier for the owner of the module being verified by the authentication service; at least one processor arranged to change an owner identifier in a data record stored in the data store from a first owner ID to a second owner ID in response to data received from a user corresponding to the first owner ID; or at least one processor arranged to transfer the at least one field defining a property of the module from a first data record comprising a first module ID and a first owner ID to a second data record comprising a second module ID in response to data received from a user corresponding to the first owner ID.