We need to be careful when creating users.

In general, users should be created through the Add client interface. This will first create a client and then an associated user. Then the created user can be edited and associated with other clients if necessary.

The idea behind this is most of the time, people will require their own clients to manage their sites. This includes workers, which will have their own sites hosted here. Customers will also have their own "client" to which users will be given access to.