It's generally held that if you serve a webpage you grant an implicit licence to do what's required to the incoming signal to it in order to enjoy what's served

It's generally held that if you serve a webpage you grant an implicit licence to do what's required to the incoming signal to it in order to enjoy what's served. I think it's wrong to think you even need a copyright licence to do it (see above), but there you go. If you want to restrict usage of your website, don't use copyright, use a standard contract. You provide a service (serving a resource, e.g. a page) if a user accepts your terms of service. Also use technological measures: if your ToS aren't accepted, don't accept requests for that page. If you really want to restrict use of your site, make your site a walled garden; anybody not accepting your ToS before consuming your content then is committing digital trespass or even fraud, contrary to the Computer Misuse Act (UK). Copyright is redundant here.