Search Engine Filter

This filter optimizes search result pages generated by major search engines (currently Google, Yahoo, and MSN Search are supported). Two things are done:

• Click tracking is neutralized, which both speeds up surfing and protects the user's privacy.
• Sponsored links may be optionally deleted, so the user sees only trully relevant results.

How Click Tracking Works

Google

Links on Google search results page look something like this (irrelevant attributes omitted; we assume that the link points to www.yourlink.com site):

<a href="http://www.yourlink.com" onmousedown="return clk(this,'res',1,'')">

When you click on the link the clk() function fetches a “beacon” from Goggle server. Information about what you where looking for and which link you chose to visit is encoded in the beacon's URL and cookies, so that the server can save it for future use (e.g. to track your search patterns in order to show you better targeted ads).

function clk(el,ct,cd,sg) {
  if (document.images) {
    (new Image()).src="/url?sa=T&ct="+escape(ct)+"&cd="+escape(cd)+
    "&url="+escape(el.href).replace(/\+/g,"%2B")+
    "&ei=SNG9Qru8OMWUsAHVj7SwDw"+sg;
  }
  return true;
}

Foxy deletes the “onmousedown” attribute from search result links (and also neuters the clk() function), so when you click on a link you jump directly to the site you want to visit without sending information to Google server first:

<a href="http://www.yourlink.com">

Yahoo

Unlike Google, Yahoo encodes all the tracking information and the target URL in the link itself, e.g. (the line is wrapped for readability):

<a class=yschttl href="http://rds.yahoo.com/S=2766679/Kyour+search+keywords
/v=2/SID=e/TID=DFX2_9/l=WS1/R=1/SS=14994860/IPC=ca/SHE=0/H=3/;
_ylt=AtagCDh6e4NmNmGeYTJ7c9hXNyoA/SIG=11a0gph0u/EXP=1119823306
/*-http%3A//www.yourlink.com">

When you click on it, you actually jump to Yahoo server, which processes and saves the tracking information, and then sends an HTTP redirect pointing your browser to the actual site. The overall result is exactly the same as in case of Google: privacy violation plus at least two extra TCP segments to exchange, which slows down your browsing and wastes your bandwidth.

Foxy converts such tracking links to links pointing directly to the site:

<a href="http://www.yourlink.com">

MSN Search

MSN Search recently introduced click tracking mechanism of their own similar to that of Yahoo. Now Foxy (version 1.0.3) handles it as well.

Parameters

delete_ads

Instructs Foxy to delete sponsored links..

Format:

delete_ads = boolean

See also Common Filter Parameters.

Please note, that this filter was specifically designed for search engine result pages, so you should not change the default URL set (unless you want to disable filtering for one of the supported search engines or something like that).

Example

type = Search Engine Filter
name = Search Engine Optimizer
enabled = true
logging = true
include = *.google.*/search
include = search.yahoo.*/search
include = search.msn.*/*results.aspx
delete_ads = true

Foxy web-based user interface will show the same filter like this: