Features Allows the user to:

Configure the methodology to dynamically obtain a fresh list of proxy servers.
- intended only for advanced users
- the default methodology works nicely
Enable the use of a proxy for all tabs, or for individual tabs.
Refresh the list of proxy servers.
Switch the proxy in use to another in the list.

Security The default list of proxy servers is obtained from a publicly available list. This has 2 important implications:

reliability
- they don't always work
- find a working proxy by:
  - allowing fallback to other proxies in list
    - which is default behavior
  - enable the proxy in a new tab
  - open the URL for a site that prints the IP of the HTTP client making the request
    - example: httpbin.org/ip
    - the IP it returns is the IP of a working proxy
  - select the working proxy in the list as the first proxy to use
security
- don't pass any private information through these proxies without using an encrypted connection
- don't ignore browser warnings for invalid HTTPS certificates
  - the proxy could be attempting to man-in-the-middle using a self-signed certificate