Kat Hagan

This plugin allows you to selectively disable comments for visitors from certain sites (e.g. reddit). If a visitor’s HTTP referer matches one of the hosts you’ve blacklisted, your post will look as if comments have been disabled (neither existing comments nor the new comment form will be shown).

Disable Comments By Referer

Ban visitors from certain sites from viewing or adding comments.

Ene Scala

The Simple Stats Total plugin allows you to collect and view page visits statistics. 
The stats is display most visited pages, referer URLs, IP addresses, web browsers and versions, visitor operating systems. 
The stats is summarized and sorted in descending order.

Simple Stats Total

Simple summary statistics on visited pages.

Disable Comments By Referer vs Simple Stats Total