Google gives a warning on its disavow links tool, that says:
This is an advanced feature and should only be used with caution. If used incorrectly, this feature can potentially harm your site's performance in Google's search results. We recommend that you only disavow backlinks if you believe that there are a considerable number of spammy, artificial, or low-quality links pointing to your site, and if you are confident that the links are causing issues for you.
What exactly is the risk of using this? If I have a bunch of spammy links that a competitor built, would there be any potential harm of disavowing them?
EDIT: In my particular case, my main site has been delisted from Google's search results, and at approximately the same time, I noticed that I've started getting a lot of spammy links to my site. No warning has been issued by Google in webmaster tools, but I want to disavow the spammy links anyway.