[Plugin: WordPress SEO by Yoast] Google crawling / 404'ing nonexistent parameter urls

http://ww.wp.xz.cn/support/topic/google-keeps-crawling-feed-urls-that-dont-exist

Google crawling / 404’ing nonexistent parameter urls in Google Webmaster Tools.

I am using %postname% pretty urls, the post urls are generally good but there are parameters added to the end that I cannot find in my database and are throwing 404’s – and would these parameters be creating duplicate content if they were found?

an example of what is happenning would be http://mysite.com/mypost/?share=twitter or http://mysite.com/?share=email or http://mysite.com/[email protected]

anybody else ? Is this anything that WP-SEO is adding to the mix? I am also using W3TC – ???

Thoughts? After going nuts trying to redirect hundreds of these bad urls I am currently trying blocking them in Google Webmasters (GW) URL Parameters I went from having 0 404’s in GW and 0 reported by 404 Redirected (404 Plugin) to currently 326 in GW and nearly 1000 by the 404 Plugin.

http://ww.wp.xz.cn/extend/plugins/wordpress-seo/

http://ww.wp.xz.cn/extend/plugins/w3-total-cache/