Making players unable to do pretty much everything?

Server Discussion
1

So, basically, I have a server players only connect to to verify their MC identity with a web app.

  1. User registers on website with their MC username
  2. User connects to the verification server
  3. User gets a clickable verification link in the chat
  4. User clicks the link, finishes the verification

Being able to see the chat and click the link are the only thing the player needs to be able to do. Is there an existing plugin that would prevent the player from doing anything else, including any kind of movement, sending chat messages etc?