In my experience, if a number of these backlinks start to pop-up it can sometimes be a sign that the site has been hacked - and that it is being used as a kind of mule or drone to feed a spam network. This is where "Fetch as googlebot" offers real help. The issue is that the parasite content is often cloaked so it's not visible to the ordinary visitor... including the webmaster!
A few years ago, I had a large network of adult sites that started using one of the widgets that I had written. The network had over 100 sites and each site had a link to my site along with the widget. I was a little worried about what that would do to my rankings as I probably only had about 300 other sites linking to me at the time.
The good news is that the links didn't seem to hurt at all in my case.
I agree - those "unwanted backlinks" are not a problem as long as you are sure your site is not being used in a parasite fashion. There was a period beginning a few years ago where a lot of adult and gambling sites were experimenting with links to authoritative sites. I saw a lot of it, and never saw a problem.
While Google has stated that it doesn't, I would be very cautious in this. It all depends on the level of authority of your website and # of questionable links that you have. If that proportion is not in your favour, it could very well reduce the trust level on your domain
Yes this is true. Google does hand out penalties for backlink anchor text overoptimization and for link spamming.
We've detected that some of your site's pages may be using techniques that are outside Google's Webmaster Guidelines. Specifically, look for possibly artificial or unnatural links pointing to your site that could be intended to manipulate PageRank. Examples of unnatural linking could include buying links to pass PageRank or participating in link schemes. We encourage you to make changes to your site so that it meets our quality guidelines. Once you've made these changes, please submit your site for reconsideration in Google's search results. If you find unnatural links to your site that you are unable to control or remove, please provide the details in your reconsideration request. If you have any questions about how to resolve this issue, please see our Webmaster Help Forum for support. Sincerely, Google Search Quality Team
No Tedester.. i am not taking about onpage links..so no website hack question is here..I am taking about offpage backlinks
I think it's funny that one of, if not the, most experienced person on these forums is trying to give the guy some good advice and he says "No Tedster..." and just dismisses it.
Sunnyujjawal Tedster knows what a backlink is. What he was TRYING to tell you is that someone could be laundering some spammy #*$! links through your site and then having your site either show their content, or link to their site when Google visits. It would be like a criminal laundering stolen money or drug money through a legitimate business.
But I don't know why any of us take the time to explain something to someone who thinks they know all the answers anyway. Sunnyujjawal's comment is exactly the type of thing that keeps me off the forums most of the time.