Disavow tool launched almost a year back by Google and ever since it has become a hot topic of discussion among webmasters and SEO. It is most commonly used by SEOs and webmasters but it might have been of some danger all this time and gone unnoticed as well.
A Google Webmaster Help thread is used by Google to tell us that tool shall surely start causing damage to the sites as soon as possible. No matter such assurances are made time and again but this time they seem to be determined to prove it rather than just claiming.
Quality team member of Google, Eric kuan have this to say about the tool and impendent changes
The disavow backlinks tool should be used with caution since it can potentially harm your site’s performance. However, if you see a considerable number of spammy, artificial, or low-quality links point to your site, and you’re confident that the links are causing issues for your site, you can use the disavow tool to disavow those links. In most cases, Google can assess which links to trust without additional guidance, so most normal or typical sites will not need to use this tool.
It should come as no surprise that Links that are actually beneficial to increasing the traffic of your site, if disavowed then you surely shall be losing a pertinent traffic. Simplest trick to not lost such links to not go out there and start disavowing links about which you might be afraid. So go slow and keep patience with your links