Add screening by IP address. When deleting a user as a spammer, block all signups from the same IP address.

spec/controllers/admin/screened_ip_addresses_controller_spec.rb

@@ -0,0 +1,22 @@
+require 'spec_helper'
+
+describe Admin::ScreenedIpAddressesController do
+  it "is a subclass of AdminController" do
+    (Admin::ScreenedIpAddressesController < Admin::AdminController).should be_true
+  end
+
+  let!(:user) { log_in(:admin) }
+
+  context '.index' do
+    before do
+      xhr :get, :index
+    end
+
+    subject { response }
+    it { should be_success }
+
+    it 'returns JSON' do
+      ::JSON.parse(subject.body).should be_a(Array)
+    end
+  end
+end