Actually, I want to know that can competitor hurt my website ranking. I am seeing, somebody is doing negative activities for my website. Before three days ago I have checked my google webmaster account. I have seen that, there are more than thousand 404 pages in the account, and then I have checked that, from where am I getting these links (404 links)? There were lots of classifieds sites, where somebody posted my website link wrongly (put broken link). I had got this site emoment.net, which has 5018 links to my website and total links 17028, i have in google webmaster account. I am still safe; I have not got any negative effect till now. But i am confused, Will I take it seriously or ignore?
I think that you should take that very seriously. It may well be that one of your competitors is trying to get your site penalized, so that you can get out of the way. I would suggest you to contact those sites by proving them that you are the owner of the site that you are talking about and have them removed all your links. Otherwise, it may not take too long before your site can be hit by a penalty.