In order to protect the quality of our search results, we take automated and manual actions against sites that violate our Webmaster Guidelines. When your site has a manual action taken, you can confirm in the [Manual Actions] page in Search Console which part of your site the action was taken and why. After fixing the site, you can send a reconsideration request to Google. Many webmasters are getting their manual action revoked by going through the process.
However, some sites violate the Webmaster Guidelines repeatedly after successfully going through the reconsideration process. For example, a webmaster who received a Manual Action notification based on an unnatural link to another site may nofollow the link, submit a reconsideration request, then, after successfully being reconsidered, delete the nofollow for the link. Such repeated violations may make a successful reconsideration process more difficult to achieve. Especially when the repeated violation is done with a clear intention to spam, further action may be taken on the site.
In order to avoid such situations, we recommend that webmasters avoid violating our Webmaster Guidelines, let alone repeating it. We, the Search Quality Team, will continue to protect users by removing spam from our search results.