Google's Matt Cutts: Typically Nofollow Links Cannot Hurt Your Site
Posted: September 11, 2013 by Alex Chan
Matt Cutts, Google's head of search spam, published a video on the Google Webmaster YouTube channel yesterday on the question of, "Can nofollow links hurt your site?" Even though the answer is generally no, there is still a "corner case."
According to Cutts, nofollow links are nothing to worry about unless you are spamming on a massive scale. In this case, Google reserve the right to take some manual spam action.
Since, nofollow links are dropped out of the link graph as Google crawls the web, they will not affect search rankings from an algorithmic point of view. Just make sure you are not hammering the web with blog comments and forum posts.
You can check out the video above for more information.