Yep, it is FINALLY here!
Google announced their “link disavow tool.”

What does it do?

“If you believe your site’s ranking is being harmed by low-quality links you do not control, you can ask Google not to take them into account when assessing your site.”

The tool can be found here:

https://www.google.com/webmasters/tools/disavow-links-main

To sum up, my takeaways are:

1. Let the sleeping dogs lie.

2. If you do have the time and desire to go through hundreds/thousands of links, ask the originating site to remove the links BEFORE using disavow tool.

3. Google reserves the right to take action or ignore your request altogether.

4. If it’s the former, it’ll still take weeks.

5. Let the sleeping dogs lie.

6. This is for sites that were definitely affected by Google’s Penguin update.

7. You really need to know for a fact that these are THE links with the negative impact before disavowing them.

8. This tool MIGHT combat negative SEO (or at least create an appearance that Google is doing something about it).

9. If you never received the “unnatural links” warning from Google, DON’T worry about this tool.

10. The best thing to do: Let the sleeping dogs lie. I mean it.

And now you, too, are in the know…

Disavowing Links
Cutts warned that the tool should be used with caution. He also warned that publishers should first try to remove links they are concerned about pointing at them by first working with site owners hosting links or with companies they may have purchased links through.

The format will be to list URLs in a text file, either individually or to exclude all links from a particular site using domain: format like this:

domain:google.com
domain:yahoo.com

domain:facebook.com

Both formats can be mixed into a single file, as shown below in an example from Google’s blog post about the new tool:

In this example, lines that begin with a pound sign (#) are considered comments and Google ignores them
The “domain:” keyword indicates that you’d like to disavow links from all pages on a particular site (in this case, “spamdomain1.com”).

You can also request to disavow links on specific pages (in this case, three individual pages on spamdomain2.com).
Who Needs To Disavow?

Who should use the new tool? It’s been primarily designed for those who were impacted by Google’s Penguin Update, which in particular hit web sites that may have purchased links or gained them through spamming.

In the wake of Penguin, panic ensued among some SEOs and publishers. Some wanted a way to ensure that they could discount bad links and start fresh. Others worried that people might point bad links at their sites in an attempt to harm them with “negative SEO.” A new business of people charging to remove links was even born.

Things got worse in the summer when Google released a new set of link warnings that didn’t clarify if publishers really had a problem they needed to fix — if they could — or not.

How Google Created Its Own Disavow Links Monster

Of course, Google wouldn’t need a disavow link tool if it hadn’t been shifting over the past months to consider bad links a type of negative vote against the site. In the past, Google typically had just ignored bad links.

But by counting bad links as negative votes, Google largely enabled some of the concerns about negative SEO that it hopes, in part, to calm with the new tool. Again from its post:

In general, Google works hard to prevent other webmasters from being able to harm your ranking. However, if you’re worried that some backlinks might be affecting your site’s reputation, you can use the Disavow Links tool to indicate to Google that those links should be ignored. Again, we build our algorithms with an eye to preventing negative SEO, so the vast majority of webmasters don’t need to worry about negative SEO at all.

I asked Cutts why Google doesn’t simply discount bad links, rather than considering some of them as potentially negative votes. After all, while it’s nice to have this new tool, it would be even better not to need it at all.

As I wrote earlier this year when covering the increasingly creaky link counting system that both Google and Bing rely on:

Links suck. It’s hard to get good links, and even when you do, you might find they don’t count. Meanwhile, who wants to be wasting time “disavowing” links? There’s got to be a better way.

Rather than answer my question, Cutts instead focused on the benefits the new tool brings, especially the ability for people to “clean slate” web sites that may have bad links pointing at them.

Aren’t you glad you have me to keep tabs on stuff?

PS : a part of this article was written by Ana Hoffman.