Someone (maybe my Competitors) open a subdomain on tumblr.com.
Just like keywordxxx.tumblr.com , and use following script to redirect to my website.
var s=document.referrer; if(s.indexOf("google")>0 || s.indexOf("bing")>0 || s.indexOf("yahoo")>0 || s.indexOf ("aol")>0){ self.location='mywebsiteurl'; }
so , If anyone seach in google ,and click on keywordxxx.tumblr.com , this script will direct the user to my website. I have found many cases like that, is that harmful ? how can i avoid that?