In the Blog Extension, there is an Option to deactivate the Gravatar Service for Blog-Comments. But the Option doesn't work. Gravatar is not deactivated and all new Comments have the Connection to Automatic Gravatar Service and shows the Avatar.
In the Source Code of the Blog-Entries there are this Line:
<img class="uk-comment-avatar" width="40" height="40" :alt="comment.author" v-gravatar="comment.email">