Selected answers from the Dumb SEO Questions G+ community.
Ammon Johns: I would be amazed if it couldn`t, but the nature of the sources, and the nature of how it could hurt (whether by algorithm, or whether it simply pushes the site to a manual review) would be open to debate and speculation.
Rob Woods: I think this is one reason Google wanted disavows in the first place. 100s or 1000s of disavow files naming the same site could flag a review or even a "this site never passes link value" setting for Goog.
Ammon Johns: There is still a possibility that a disavow list isn`t used in the algorithms as such at all - only used at the point of a manual review for reinclusion to see if the webmaster has made enough effort to clean up where many of the sites in question might be unwilling to remove those old bad links that the algo was already devaluing/discounting.
Alan Bleiweiss: I agree with all of these responses. To sum up: "Maybe, maybe not".
Maria Patterson: I manage a site which has had tens of thousands of backlinks pointed to specific categories from bad domains - porn sites, pay loans you name it it had it thrown at it. Disavowed and every week someone checks for bad backlinks and manually reviews them as this site gets many good backlinks naturally from reputable high authority sites. A painful process and 750+ domains are disavowed to date. The negative SEO slowed down for a few months and then came back with a vengeance in Oct 17 (started Oct 16). Just in time for Christmas and I could see other similar sites with same types of categories were attacked so believe it is a competitor and have one in mind. First hand experience of how effective a disavow file can be and what happens if you don`t act.
Roger Montti: Whoa Rob, Google didn`t want disavows. A way to disavow was suggested by the SEO community and Google resisted the idea for a couple months then eventually changed it`s mind.
Michael Icon King: I would be surprised if they weren`t part of how the penguin classifier was trained
Ryan Jones: From what Google has told us, Disavow isn’t used in the algorithm at all. It’s used at crawl and or indexing time. If they see a link that’s disavowed they treat it the same as a nofollow.
Jenny Halasz: No no no. Disavow is not used in the algorithm. It couldn`t be. How many of you have disavowed your links from bbb.org? Yet it remains such a high trust site that Google actually uses it in their quality rater guidelines. Or the joeant directory is another example. This is one of my least favorite myths. There is no way that Google could take a signal like disavow and use it to make a quality judgment about the site itself. It`s as absurd a "ranking factor" as direct traffic or bounce rate.