There is a WebmasterWorld thread which has an SEO who accidentally removed all the links from their disavow file and a week later, his traffic to his web site "soared" he said.
Here is his timeline:
- 22nd Nov - Disavow file overwritten by mistake. Some domains previously disavowed, re-avowed as a result. The error went unnoticed until over 10 days.
- 29th Nov - Organic traffic from Google increases by over 100 percent and currently has highest ever traffic.
There were no official or unofficial Google updates on the 29th of November. So I doubt it was related to an algorithmic change.
But truth is, many of the links that webmaster may have disavowed may have been working well for the site to rank in Google. By him removing the disavow, it may have triggered Google to count the links again and thus have the site ranking boost up and see his traffic "soar" for his site.
The question he is now asking is should he start disavowing some or all of those links again, in fear of a link or Penguin penalty?
There is an interesting debate going on in the forums, so make sure to check it out.
Just in case newbies read this: This is incredibly dangerous and I don't recommend you do this without care. Removing all your links in your disavow file can get you in a huge amount of trouble. If you try this, be warned. In the case above, it can be related to the link removal in the disavow or one of the other hundreds of factors in Google's algorithm. This is just one case, where we know limited information.
Forum discussion at WebmasterWorld.