I worked on a project where the site uses HTTP. Initially I did a double take as using requires a login, thinking that's just wrong.

But after a bit of reflection I now think that in this specific case there's nothing bad about using http. Services are offered on a first come first serve basis to a large but closed group of valid users. Key is that there are a bunch of real world processes that follow the initial trigger with no practical way for any other party to benefit.

The site is extremely simple but blazingly fast.