Block VPN/Proxy and Tor users

// Getting the anonymity status from the user's IP
$.get("https://api.ipdata.co?api-key=<<apiKey>>", function (response) {
  if (response.threat.is_anonymous) {
    alert("You are not allowed to create an account.");
    }
}, "jsonp");

This simple example shows "You are not allowed to create an account." if is_anonymous is true . You can replace it with more complex handling such as preventing the user from signing up or requiring a credit card.
You might also choose to allow Tor users through and only block users using proxies.

// Getting the anonymity status from the user's IP
$.get("https://api.ipdata.co?api-key=<<apiKey>>", function (response) {
  if (response.threat.is_proxy) {
    alert("You are not allowed to create an account.");
    }
}, "jsonp");

You also have the option of blocking users whose IP's have been reported repeatedly by admins across the internet for malicious activity or spam. To do this simply block if the following fields are true;

• is_known_abuser - to block IPs that have been reported to be sources of spam
• is_known_attacker - to block IPs that have been reported to be the source of malicious activity

We aggregate and regularly update our lists from high quality, authoritative sources to develop our dataset of more than 600M malicious IP Addresses, spammers, open proxies and Tor exit nodes.