Blue Coat allows access to some sites and blocks other sites, depending on your configuration. I look at high risk configuring. It lets me allow some applications and block others.

We use the on-premises version.

Our use cases depend on the customer. The requirement may be for HTTP object caching, URL filtering, or website categorization. It also depends on the user's best practice policies.

I am an occasional user. Our IT team primarily uses it. My primary use case of this solution is for web content filtering.