run this in the console on a twitter user's following / follower page to export the IDs of all their followers / followeds in a format suitable for blockchain import

blocklist_export.js

var IDs = [];
var users = [];
var result = '{"users":[\n';
var elements = Array.prototype.slice.apply(document.querySelectorAll("div[role='listitem'] div[data-user-id][data-screen-name].ProfileCard"));
elements.forEach(function(element) {
	var user = {id: element.getAttribute("data-user-id"), name: element.getAttribute("data-screen-name")};
	IDs.push(user.id);
	result += '{"id":"' + user.id + '"},\n';
});

result = result.slice(0, result.length-2);
result += '\n]}';

var element = document.createElement('a');
element.setAttribute('href', 'data:text/plain;charset=utf-8,' + result);
element.setAttribute('download', "result.txt");

element.style.display = 'none';
document.body.appendChild(element);

element.click();

document.body.removeChild(element);