Web Blog of Greg Mathews

In theory a proxy server allows a user to surf the web anonymously, many students use a proxy to bypass school restrictions when surfing using the school network.

This week I discovered that a visitor to your site via a proxy could be detrimental, while checking the Google search results for one of my sites I found one such proxy imsosneaky.com actually stores the urls that people visit via their proxy and these urls get indexed in the search engine results. Go to Google and try the command site:imsosneaky.com and browse the results, you will find clone’s of pages on Yahoo and many other big sites.

Now this could lead to problems, ie Google punish sites for duplicate content, so in theory the proxy server should be dropped down the results pages but what happens if Google punish you rather than the proxy?

Further investigation found that there are a number of proxy sites that use scripts such as proxy.cgi, a perl script proxy server. By default when a visitor uses these proxies to visit your site, javascript is disabled which could effect the web site in various ways such as :

1. Javascript menu’s would not work

2. Any sites utalizing ajax would not work

3. If using remote statistics on the site many of these require javascript, these would not work so the traffic via the proxy servers would not be tracked.

4. Adsense would not work on your site, this means that the webmaster is potentially loosing earnings as no visitor via these proxy servers would see nor click on adsense ads displayed on your site.

Many of these proxy servers use a single IP address, this means if the user does enable javascript they all appear to be from the same IP, so if they click on the adsense ads on your site it could lead to click fraud.

It is hard to keep track of these proxy server sites but I have decided to forbid some from accessing my site, I did this by adding the following to my httpd.conf although you should be able to do the same in your .htaccess file:

RewriteEngine on
RewriteCond %{REMOTE_ADDR} ^72\.232\.86\.218 [NC,OR]
RewriteCond %{REMOTE_ADDR} ^67\.159\.45\.52 [NC,OR]
RewriteCond %{REMOTE_ADDR} ^67\.159\.44\.138 [NC,OR]
RewriteCond %{REMOTE_ADDR} ^85\.195\.119\.22 [NC,OR]
RewriteCond %{REMOTE_ADDR} ^72\.232\.82\.122 [NC,OR]
RewriteCond %{REMOTE_ADDR} ^64\.72\.116\.210
RewriteRule ^/.* - [F,L]

This redirects any visitor that has one of the IP addresses above to a forbidden message, my attitude is why should I pay for bandwidth and the risk of click fraud when there is very little chance of earning from these visitors?