Selected answers from the Dumb SEO Questions G+ community.
Tina Halkj�r Jensen: Hi, Does anyone of you have experience with disavowing links? And if, did you disavow high risk links or did you get hit by Google Penguin or got a warning in GWT? Thank you in advance :)
Edwin Jonk: Google penguin is a algorithm penalty and a warning in GWT is a manual penalty . These two are quite different and you can be hit by both. ;
Google calls a manual penalty a manual action: " While Google relies on algorithms to evaluate and constantly improve search quality, we're also willing to take manual action on sites that use spammy techniques, such as demoting them or even removing them from our search results altogether. "  In short, when you have a manual penalty about links you need to do more than only submitting a disavow list. 
The penguin update is an algorithm penalty and Google says that you can use the disavow to help you to recover from this. The problem with this is that you have to wait until Google updates. 
 ;  ;  ;
Nebojsa Djukic: You should ;disavow all backlinks that are obviously spammy. Before you do that try to contact website owners and ask them to remove links to your website.