ourwave

The Escape Button is a simple floating action button that allows users to quickly and safely exit your website in case of emergency. We originally developed this tool to support survivors of sexual and domestic violence and hope it can be useful for the community as well.
The Escape Button is built to handle both situations where the user or browser does not have Javascript enabled and when it does.
It is possible to override the styling of the Escape Button in your own stylesheet.
https://www.ourwave.org/developers

Escape Button

We developed the Our Wave Escape Button (available in the bottom right of our website) to help protect our users in unsafe situations.

stasionok

With this simple plugin you can restrict extra external requests made with internal WordPress WP_Http class. 
Just put in the filter rules field what you wish to restrict. One url part or url regex per line. 
By default, the plugin returns WP_Error answer for restricted requests. But you can put in response your custom response data.

ROB (rat out blocker)

Restrict execution of certain external requests with partial url or even regex to prevent personal data leakage (as example)

Escape Button vs ROB (rat out blocker)