enigma1 - 1:13 pm on Apr 27, 2011 (gmt 0)
I 301 redirect to remove *every* unknown or un-needed parameter.
Ok how are you going to parse a url like this?
With php for example they won't even show up in the global $_GET array. Now you going to start parsing the request for an infinite number of combinations. It can get so complicated and your scripts can introduce errors and significant latencies. You can inject arrays as parameter names, various empty fields and so forth, just use your imagination.
This is what JohnMu posted a year ago:
As long as you remove the problematic content on your site, you can ignore the external, spammy links to that content. Our algorithms understand that you can't control everything outside of your site, but we do expect that you could do that within your site
This is what they posted about the parameter handling feature in the WMT that was introduced long ago.
Google lists the parameters they’ve found in the URLs on your site
"in the URLs on your site" not external urls but "on your site". Why they would bother to do all this if the external URL poisoning wasn't handled by the search engine?