I have noticed that a couple of my home page links in the Google Results have url variables added that didn't come from my site.
The variables are not used so therefore ignored and my site just displays it's homepage.
What I don't want to happen here is a duplicate content issue. Obviously someone has for some reason linked to my site with this url either on purpose or mistake and Google has found it and spidered the page.
Is this a cause for any concern?