I check webmastertools for 404's.
I can see other sites linking to my site but with additional characters which makes the link a 404 in my site.
if i have a url like sitename.com/category/product-name.html and other sites read this content from some other source and are listing in their site like
because of such improper link backs(which i did not create in that site) i get a lot of 404's in webmastertools.
how do we prevent this?