As we all know, Google makes frequent changes to its search engine algorithm to keep up to date on the latest trends in search and to provide its users with the most relevant content. Recently, Google has been focused on mobile browsing, making changes that reward websites that fit their definition of mobile-friendly. These types of updates are ongoing and web developers constantly need to keep up to date to make sure their websites are ranking as best as they can. While there are frequent updates to the algorithm, there has been one constant in the world of SEO for years now: if high-quality websites link to you, you’ll be rewarded in the organic search rankings. Conversely, if a lot of spammy low-quality links link to your website, you’ll be penalized.

Building these types of links are a component of an SEO campaign called “off-page SEO.” On-page SEO remains pretty straightforward. Build your website correctly, tag everything properly, fill it with useful and original content and Google will like what it sees. Off-page SEO is a bit trickier. It can take time to build the right links from the right places. You don’t want to add a lot of lower-quality links that Google might deem too spammy later on. And there’s one other thing: other people can potentially sabotage your website using negative SEO tactics.

On-page SEO is under your control. Unless you’re hacked, you’re in charge of what content goes up on your website. Off-page SEO is something that is just out on the internet. Ideally, only you and people who value your website are backlinking to it. But what if someone had malicious intent against you and wanted to hurt your rankings? Would they really be able to sink your website’s ranking by working to undo all of the hard work you put into optimizing it for Google?

As Marie Haynes points out in her Moz post about negative SEO, Google once had a page on their website stating "There is nothing a competitor can do to harm your ranking or have your site removed from our index." In 2003, however, Google updated that language to read "There is almost nothing a competitor can do to harm your ranking…." (emphasis added). A lot has changed about SEO since that statement was modified, but Google’s stance today remains pretty close the amended statement--that true negative SEO that actually affects a site’s rankings is pretty rare. In June 2013 Google’s Webmaster Trends Analyst John Mueller had this to say about the prevalence of negative SEO: “With negative SEO, most people mean that a competitor is creating bad links for your website…we work really hard to prevent these things from causing any problems. We work hard on our algorithms to try to recognize these kind of problems and catch them ahead of time.”

Of course, Google has every incentive to convince you that it can tell the difference between good links meant to help your rankings and malicious links intended to sink the ship. After all, if Google can’t tell the difference, its algorithm and methods lose a lot of credibility. For the sake of argument, we can take Google at its word that it’s doing everything possible to fight negative SEO. Perhaps the practice is rare. Just don’t tell that to someone who has been at the wrong end of malicious backlinking tactics. They would certainly tell you that negative SEO is indeed very real.

Forbes contributor Jayson DeMers relates how he received an email threatening to build thousands of poor-quality links to his website if he didn’t pay the sender $250. What did DeMers do? Well, since he’s an SEO expert familiar with negative SEO tactics, he did what you should do every time you get an email from a Nigerian prince: he simply ignored it. Could the extortionist follow through on their threat? Sure, but in reality the con artist was probably going for an easy mark who would just panic and pay them the money. After all, the type of person who would concoct such a plan probably wouldn’t want to do the work of building all of those bad links just out of spite. They’re just as well off to move on to an easier target.

There’s another reason DeMers chose to ignore the email. He knew about the Disavow Tool in the Search Console. To help ease the concerns of webmasters worried about negative SEO tactics, it created an option to disavow backlinks to the website that are suspected of being low-quality and/or related to negative SEO tactics. With the Disavow Tool, web developers can notify Google about suspicious links that they no longer want to be associated with their website. If it seems like the links are coming from a few common sources, you can even remove entire domains from your website’s link profile using the Disavow Tool.

DeMers points out that Google claims they created the Disavow Tool primarily for webmasters to correct their own mistakes. In other words, if you feel like you made some bad decisions about backlinks a few years ago, you could now tell Google to ignore certain backlinks. But whether the bad links are your own doing or if they are part of a legitimate negative SEO attack, the Disavow Tool is there for you to use. Google doesn’t want to suggest that negative SEO is more prevalent than it is willing to admit, but at least it provides a tool to deal with negative backlinks.

You may be wondering--wouldn’t it be illegal to willingly target a competitor's website with negative SEO tactics like this? There’s not a clear answer on that yet. DeMers’ story describes a clear case of extortion, but who knows where the threat really came from? If the sender is in Asia or Eastern Europe or Africa, there’s little chance that local authorities would be willing to prosecute, especially when the ransom is so petty. In cases of nefarious webmasters trying to sink competitors’ sites, there’s an even smaller chance of prosecution. How could you prove who created those bad links to your website, anyway?

Your best path forward is to take what Google says about negative SEO with a grain of salt. The practice might be rare, but it’s not impossible. If you think you have been a victim of negative SEO, check out your link profile on the Search Console and remove any suspicious links just to be safe.